Miche hubs are simple to service. 

Play in Axle:this can be adjusted out. First make sure the end caps a tight. Use two 5mm allen keys and note the direction arrows on the left end cap. reverse thread alert. 

Use a 2.0mm allen key to undo the grub screw on the left side. Use a 17mm spanner to adjust the bearing preload adjuster so there is just no play. screw down the grub screw. Be gentle with it as grub screws are easily rounded of. It only has to be secure so the adjuster does not unwind by itself. 

The adjustment is best carried out with the wheel clamped by the QR in the frame as QR pressure loads the bearings. 

Proceedure for the front and rear hub is the same. 

Freehub change:

If you chanaging your freehub due to notching then so you cassette lockring up tighter. 40Nm is the minimum required. Miche cassettes also notch shimano pattern bodies less so there your other solution. 

Undo the end caps with two 5mm aleen keys in each end cap noting the direction arrows on the left end cap. Remove the axle and change freehub. 

Assembly is the reverse of disassembly but bearing preload may need to be set again. 

Bearing Replacement

The freehub bearings can be replaced but most users will lack the bearing extraction tools to make this possible. walking the bearings out will likely damage the freehub or get the bearing stuck. 

Main shell bearings should be extracted with bearing extracter or kocked out carefully. A bearing press should be used to press in new bearings. The Miche supplied 6001C3 bearing shoudl be used. a standard 6001 bearing will fit but will wear out faster because its not a clearance bearing.