Boardman comp BB. DIY or get shop to do it?

grawp

I need to service/change my bottom bracket. It's specced as a Truvative GXP on the website. Being fairly handy I like to do stuff myself but am new to modern biking and it's a steep learning curve. Can I have a list of what tools I'll need to do the job. I'm expecting to need an 8mm crank hex key and a splined tool to fit the BB (will a standard Shimano tool do this?). Also should I be looking to just get new bearings or is it the norm just to replace the whole assembly? Are there different brands that'll fit this frame?
Future jobs will include changing the bearings in the head and cleaning/changing the bearings in the rear hub.
Does it make sense to buy a tool kit at this point or get specific tools as I need them? Or financially is it best to give it to a shop to do?
Finally does anyone know a website where I can get detailed info on the boardman inc bearing types/sizes and compatible options?

nicklouse

all the info is on Park tools site.

you need one allen key and a External BB tool.

remember how the BB spacers are and fit them the same way.