What bottom bracket do I need for a decathlon rockrider 5.0 The bottom bracket on my Rockrider 5.0 has a little too much play in it so I figured it best to change it before I get a failure whilst I'm commuting. Does anyone know which bottom bracket I would need for it? Or advise on how I can find out? Also any ideas on what type of extraction/fitting tool I may need for this type of bottom bracket? 
Thanks in advanced
I can't precisely tell you which one you need with a picture, and I didn't find a good one in the internet. The bottom bracket you need is either an OctaLink or a Square bottom bracket. You should be able to figure out just by looking at your bike.

Before buying you need to check both the shell and the spindle lengths, as you can see here.

It is really easy to remove and install a new one, but you will need to buy a crank extractor and a bottom bracket removal tool. These aren't tools you will use very much so just get the cheapest ones you can find. You will also need generic tools to unscrew the crank, but you can figure these ones out.

You can find detailed instructions on how to do this here, or just search for a youtube video. Before installing the new one grease the hell out of those threads so it won't be a pain to remove next time, and because that part is very exposed to the elements. Stupid elements!