Are you 100% sure it is asbestos?
Asbestos was banned in 1985 so if the roofing material is less than 27 years old, it's not asbestos. If I recall from my days in the waste management business, if it's between that and about 40-45 years old, it may or may not be asbestos and if it's older than that, it almost certainly is asbestos.
A lot of people still refer to modern corrugated roofing as 'asbestos' when it actually contains no asbestos.
Might be worth checking how old it is.
I'm almost certain it's asbestos (or at least the chance is very high). The garage is a nasty prefab concrete affair, and the roof was original. The garage was built in the 1960s.