My cranks had loads of play in them and I was getting all sorts of noises from around my chainrings. So as neither had been changed since I bought my Specialized StumpJumper SFR 120 bike in 2005 I went for an upgrade.

I swapped out my Old Hollowtech cranks, chainrings and separate Bottom Bracket cartridge for a fully integrated Shimano XT cranks, chainrings and bottom bracket set. This comprehensive Bike Surgery post covers a video tutorial and article on the removal of the cranks and bottom brackets. There is a seperate one for installing the new ones.

• Get your bike ready and tools to hand
• Lets talk tools. I used an adjustable spanner/ wrench, a BBB ISIS or Square crank removal tool, a Bottom Bracket tool for installing and removing Shimano® and ISIS Drive® spined 20-tooth bottom bracket cups (pic on right).and some Allen Keys, lots of rags and kitchen roll. The other items in the pic i.e. the tape measure, the bottom bracket spanner and the lube I used for putting on the new gear in the other tutorial.
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• First of all I took out the screw holding in the crank arm with an Allen key.
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• Once off I then attached the BBB ISIS or Square crank extractor tool by screwing it in with my hand
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• Then I tightened it on the inner nut (closest to the bike) with a spanner
• Then moving the spanner to the outer nut (furthest from the bike) I screw until the pressure of the spindle on the inside of this tool pushed the cranks and chain ring away from the bike.
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• NB: If you were changing your chain rings this would be the same process up to this point.
• Right go round to the other side of the bike and do the same i.e. take of the crank screw with an Allen key, attach the BBB tool and and remove the crank arm.
• Once all is removed the Bottom bracket is exposed on both sides. Starting with the non drive side (other side from where the chainrings were) you then insert the Bottom Bracket tool for removing 20 tooth bottom bracket cups.
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• Fit it in snugly and turn with a an adjustable spanner / wrench
• Then go round and do the other side and voila the Bottom Bracket will slide out.
• Clean and lube
• Go put the kettle on

Check out Post for installing the integrated Shimano XT Bottom braket crank set.