RHD Brake pedal linkage

[benczuk]

My Brake pedal is slow to return. Everything else works fine (brakes function fine, pedal has good feel, new calipers fitted etc) which leaves the return spring in the servo (?) or the linkage.

I plan to start by checking the linkage is free, does this run inside the cabin, or in the engine bay? how much of a pig is it to get to? Anyone have pics / diagram?