>step 1
launch 10 multiwire tether satellites to orbit Jupiter in the same orbital path as Europa each with 20 kw micronuclear reactors to power the 1000 Kilovolt current in the tether. This electrostatic field Ejects energetic particles from that orbit, and prevents new particles reaching equilibrium in the section of Jupiter's Van Allen belt that is Europa, within 100 days radiation levels are 1% of what they were and within 1 year they are earthlike levels.
>step 2
drill a tunnel through the thinnest part of Europa's ice crust a few km deep ( this is possible because temperatures would be low and pressures increase 7.7x slower with depth than on earth).
>step 3
transport 1-10 gigatons of methane clathrate ice from the underside of the ice crust to the surface ( this is about mass of the oil produced each year on earth)
>step 4
now at the surface of Europa the methane clathrate is no longer stable and methane leaks into the thin atmosphere of Europa, once the total 1-10 gigatons of methane has been leaked to the atmosphere the satellites are turned off and radiation rapidly increases, within 1 year all the methane has undergone radiolysis and covered the total surface of Europa with 0.1-1 mm of tholins lowering the albedo to 0.1-0.05 raising mean temperatures to -100Celcius.
>step 5
turn satellites back on to reduce radiation levels to earth levels
>step 6
release enough methane to raise temps to -97celcius