It looks like a typical Denso Mini alternator. If it is, then everything is serviced from the back cover. You can take the brushes out thru the back with out splitting the alternator case.
I have one that failed to make voltage after a few hours in service. The plastic boxes that hold the brushes were too tight, the brushes wore a bit and lost contact with the slip rings. The Rebuilder (his actual buisness name) sold me new brush boxes for $6.
Gotta love that Mini Denso...
About alternator service life: The high RPM caused by the pulley ratio shortens the brush & bearing life. I think full alternator output is @ 6000 RPM.
I measured a Denso alternator pulley a few days ago, if I recall correctly, it was about 2.75". Used with a 9.75" Lycoming pulley:
9.75 / 2.75 = 3.54:1
3.54 x 2700 = 9572 Alternator RPM
Canton Racing makes a 3.25" pulley for the 15MM shaft Denso and other metric alternators.
https://www.cantonracingproducts.co...DIA-V-BELT-ALTERNATOR-PULLEY-WITH-15MM-SHAFT/
Lycoming flywheels are made with 9 3/4" or 7 1/2" pulleys.
9.75 / 3.25 = 3:1
3 x 2700 = 8100 Alternator RPM
7.5 / 3.25= 2.3:1
2.3:1 x 2700 = 6230 Alternator RPM
I have 7 1/2" on my O-360. I feel inclined to try the Canton pulley, the alternator RPM would be right in the sweet spot for flight, although output might be low during ground operations.