Can anybody give me a hint where in Chiang Mai I could use a hydraulic (hand-)press to press some bearings (the largest is 60 mm in diameter) out and the new ones in?
Thanks in advance!

On the left hand side of Chang Moi Rd half way to the market. Failing that, I'd use a socket with the right diameter (and a hammer).

there's a good little machine shop on Charoen Muang, just a few doors up from Sarasas Witaed school, that has helped me a few times with this kind of thing. cheap and competent, very nice guy. the sign in thai says "rong glung" (lathe).  It's right at a zebra crossing a few steps away from soi 7.