In this instructable I will show you how I clean my skateboard bearings. I know there are many other methods out there but I use a unusual method i guess you could say...
I would not suggest externally cleaning your bearings and as paperclip32 mentioned removing your bearing cages is not advised.
Step 1: Removing Bearings
Once you have removed the wheels from the trucks the bearings should be removed by placing the wheel (with bearings inside) halfway on one of the trucks' axles' threading and pushing down on one side of the wheel.
Step 2: External Bearing Cleaning
Whipe the bearings down with a paper towel or rag and pop the seals, and remove the cages if you want. Try and remove all mud, dirt, dust or slime the might be on your bearings.
Step 3: Final Bearing Cleaning
Take your bearings and lay them down on a paper towel.
If you are using starter fluid like I am you should take your bearings outside and lay them on the ground and spray them down until they are clean and run like new again.
If you are using acetone, alcohol or a similar solvent you should place them in your bowl, or bottle, or whatever you use, and pour the solvent in and let them soak and shake them around.
If you are using a lubricant like Tri-Flow make sure you lay your bearings down on a paper towel and spray them down good so you can clean and lubricate them.
DO NOT USE WD-40! IT ATTRACTS DIRT WHICH CAN FREEZE OR JAM YOUR BEARINGS!
Step 4: Dry Your Bearings
The title says it all.
Step 5: Lubricating Your Bearings
If you are using oil or speed oil lubricant to lube your bearings you should put about 3 drops equally on each bearing.