Just did this myself recently.
Depending on what the inner skin of your house is block or timberframe.
With timberframe you can get a 4" holesaw for your drill and easily drill through the plasterboard and osb board on the timberframe. For going through blockwork you have two main options
1. Rent or borrow a 4" core drill. This cuts neatly through the block and leaves a nice even hole for the vent pipe. (You'll probably need a 110v transformer also or a "Genny")
2. Mark out your 4" circle and drill a series of holes in the block with a standard sds hammer drill and large masonary bit. Then take a bolster chisel and bang out the hole. Not as neat a finish though.
3. Pay a lad who has the equipment to do it
!!
Plan carefully first where you want to locate the vent.
Make it as convienent as possible to the vent outlet from the back of the machine.
Ensure that from the outside your vent has at least 40cm clearance from the ground level.
Make sure the hole is centered between two studs if timberframe.
Drill a small pilot hole first to check for any electrical wires or plumbing pipes behind the plasterboard.
Drill your 4" holes
Pick up a vent cover from your local builders merchants or DIY chain
Seal the edges of the vent between wall and vent pipe with expanding foam to keep out unwanted little visitors.
AndyH