1. Remove the wheel from the bike. Remove the quick release skewer from the axle. Using a chain whip to stop the cassette turning, undo the cassette lockring with a suitable lockring tool and spanner. Remove the cassette from the freehub.

2. Prise off the drive side spacer. If it is difficult to remove try two flat bladed screwdrivers opposite each other to lever it off. The spacer is made of alloy so be careful not to damage it. Remove the non drive side (coloured) spacer.
3. Pull the freehub off (a bit of gentle leverage from a screwdriver may be needed). Be careful that you don't loose any of the three pawls and springs - they might come out with the freehub or stay in the hub. Remove the internal spacer from behind the freehub.

4. Using a soft faced hammer or mallett tap the axle from the drive side. This should push the non drive side bearing out of the hub. Support the hub so that it is not damaged during this. I just use a couple of bits of wood to do this.

5. Turn the wheel over and drift out the drive side bearing. An old socket of the right size to fit in the hub does the job if you don't have the proper tool.

6. Drift out the outer bearing from the freehub. If you don't have the proper tool you can improvise as I have here! Work your way around the bearing slowly until it comes out.

Note: whacking bearings may knacker them! alternative methods for removing them can often be worked out using a g-clamp or vice combined with suitable bits of metal and wood.

7. Take out the internal spacer. Remove the circlip holding in the inner freehub bearing. Drift out the inner bearing too.
8. Decide whether or not you are going to replace or regrease the bearings. In this case I am regreasing them. To do so: prise the seals off with a stanley knife, clean the bearings up (use a degreaser if necessary) and squirt in plenty of grease. Push the seals back on. The bearings are standard 6001 and are about a fiver each if you need to replace them.
9. You should now have all these bits ready to reassemble! Basically, it's just the reverse of taking it apart.

10. Drift the inner bearing into the freehub. Replace the circlip and put a little grease on it. Insert the internal spacer and drift in the outer bearing. Make sure the spacer imbetween the bearings is just free to move.

11. Insert the drive side bearing into the hub. It will be a tight fit. Insert the axle from the non drive side. It might require a gentle tap with a soft faced hammer to get it into the drive side bearing which is also a tight fit.

12. Insert the non drive side bearing. I found a spark plug socket gave clearance over the axle to drift it in.

13. Insert the internal spacer into the drive side of the hub. Put a blob of grease on each of the holes in the freehub that the pawls fit into. Insert the pawls and springs. The grease should hold everything together. Holding the pawls in with your fingers slide the freehub into place. I have read many tips about using elastic bands etc to hold the pawls in but they are not really needed as long as you have at least three fingers and a thumb on one hand! Make sure everything is spinning freely.

14. Push both spacers back on to the ends of the axle. Refit the cassette (you don't need the chain whip to do this). Reinsert the skewer (I like to put a drop of lube on it first). Put the wheel back on the bike.

Job done!