Anyone know how to remove this bottom bracket cable cover?

Ah Hell...just unscrew it.

Put your hex wrench in the socket and give it a couple of LIGHT downward taps with a small hammer. Then try to break the screw loose. Turn CCW, of course. Even if you strip the hex socket out the screw can be removed easily with a [censored] punch and tap hammer.

I can't figure out why Spesh didn't use a stainless steel screw.

FWIW ...

[INDENT]Is the cable a traditional stainless steel cable OR is it a wire for an electronic shifter?[/INDENT]

[INDENT][INDENT]Regardless, you probably do NOT need to remove the "cover" to replace the rear derailleur cable ...

BTW. Obviously cables do not last forever AND I know that some people log thousands of miles per year, but why are you replacing your 2015 bike's cable?

[INDENT]Have you logged 10,000+ miles on your bike?

Are you changing shifters?

______?[/INDENT]
[/INDENT][/INDENT]
YOU can either fish the cable through by attaching a sufficiently long piece of ~1mm nylon cord OR other sufficiently strong cord (e.g., fishing line) or multi-stranded wire ... heck, dental floss is probably strong enough ...

[INDENT]Attach the "cord" VERY SECURELY to the end of the cable ... three-or-more inches which are wrapped-and-well-taped to the derailleur cable should be good enough ...[/INDENT]

[INDENT]PULL the old cable out of the frame until the "cord" is accessible at both ends ....

Securely attach the end of the new cable to the "cord" ...

Pull the cord back through the frame ...

Attach to the rear derailleur ...

Adjust tension ...

Done![/INDENT]

IF you have already pulled the old derailleur cable out of the frame, then you should be able to feed your new cable through the Down Tube and guide it through to the chain stay AFTER you remove the crankset (and BB's sleeve, if present) ....

[INDENT]if you have trouble guiding the cable into the chain stay then you can put a "fish" tape/cord through the chain stay where it exists near the rear derailleur, etc.

[/INDENT]

See pages 15 and 16 of 17.
http://vid.artscyclery.com/pdf/Specialized%20Tarmac%20SL4%20Pro%20Race%202014%20Complete%20User%20Manual.pdf

Easy peasy.

OP, did you get the cover off yet?

I don't know why that screw looks rusty because Specialized doesn't use anything but aluminum or stainless so that must be mud or some sort of stain. Also the allen area appears to be filled with it as well. So all you should have to do is clean it out.

Alf - as you can see from the manual Jojo has to remove that cover to thread the inner cable and not to replace the outer.

"Never in the field of human screw removal was so much owed by so many to so few."

Spesh's engineers made the job of cable replacement braindead.
Mankind has raised over-complication of a simple job to new levels of insanity.

cyclintom said:

I don't know why that screw looks rusty because Specialized doesn't use anything but aluminum or stainless so that must be mud or some sort of stain.

Makes sense. And some of the Chinese 'stainless' isn't so rust resistant. It can have a distinct tendency to 'brown' and/or develop rust spots. It could be camera lighting or a replacement bolt for a lost OEM fastener.

cyclintom said:

Alf - as you can see from the manual Jojo has to remove that cover to thread the inner cable and not to replace the outer.

Yes ...

[INDENT]Removing the cover should be easier than fishing the new cable through the frame by attaching it to the old cable ...[/INDENT]

FWIW. If jojoma is trying to follow the information in the "User Manual" PDF file and he is having difficulty removing the cover then I suspect it is because there is a conflict between the information in the PDF file and the actual bolt which is holding the WTF-is-the-need-for-it? cover in place on his frame ...

[INDENT]By my reckoning the size of that required hex is smaller than the 4mm which the diagram suggests ...

The "rusted" bolt's hex appears to be closer to 3mm ...

[INDENT]If, by chance, THAT is correct, then a 4mm Allen Wrench won't work![/INDENT]

[/INDENT]

I rest my case, your honor.