What tools (ideally cheap ones – this isn’t something I expect to do very often) do I need to remove a Hollowtech II BB, and install a SRAM GXP one? I can’t tell from online pics – will it be the same wrench for both?

This one should work to remove the old BB but you may find cheaper ones if you look around

I can’t help you with the installation tool though as I’ve never had to install a GXP bb

Slight hijack: does anyone know if the hollowtech 2 removal tool works for Raceface BB’s… I’m not even certain what type of BB it is as this will be the first time I’ve taken the cranks off the bike

Same tool will do all 3 (unless its the 30mm axle on the raceface)