I'm afraid it's not a nice job on a LHD car !
Definitely done from underneath and from memory, best to remove as many things as possible to give you some room. I don't recall disconnecting the gear linkage, but I did take off the exhaust and brackets
Re-fitting was done by connecting everything loosely (reservoir pipe, unions etc) before bolting to the chassis, and once it was all in place then tightening up
No special tools needed , but double jointed, small hands would be helpful