i think there was a thread not too long ago about this
imo leave battery connected and trickle charge in the car
start engine once a fortnight and allow to get to running temp, let the fan come on a few times, this will save the hassle of draining the fuel and keep the fuel system and engine in good condition put a gallon or so of fresh fuel in so your not picking up any crap at the bottom of the tank
fit the steelies and crappy tyres
leave the rear windows open a couple of mm and get some dessicant packs [cabinet type] off a friendly BT engineer, cut the plastic packing at the top and put 5 inside the cabin, these will soak up any moisture
leave handbrake off and either choc wheels or leave in 1st
as its only 3 or 4 months i think this is your best option

maybe also remove radio/disconnect to prevent battery drain