1. Remove the drive side crank bolt. In this example the bolt is self extracting so the crank comes off with the bolt. Usually a crank extractor will have to be used to remove the cranks.

2. Remove the non drive side bolt and crank.

3. Using the correct bottom bracket tool and suitable spanner undo the non drive side of the bottom bracket. The cup should come out leaving the bottom bracket in place.

 

4. Undo the drive side of the bottom bracket. Note: the thread on this side is left handed. The bottom bracket should come out.

5. Clean up the inside of the bottom bracket shell including the threads. Gentle use of a small wire brush may be needed.

6. Apply copper grease to the threads on the new bottom bracket and screw it in from the drive side. Be careful not to cross thread it. Remember the thread is left handed. Tighten it up.

7. Apply copper grease to the threads of the non drive side cup, insert it and tighten.

8. Grease the ends of the bottom bracket axle if it is splined or octalink (like this one). Leave square tapered axles dry. Replace the cranks and tighten the crank bolts fully.