Pretty straight forward:
1. Turn off power
2. Turn off water (hot)
3. Disconnect drain, water feed, electrical connection.
4. Lower washer -- usually jacked up slightly with leveling jacks.
5. Slide out -- be careful you don't mess up your floor -- old rug,
cardboard, piece of plywood, etc.
6. Slide in new washer - this might take some help.
7. Reconnect drain, water line, electricity. Make sure the unit is
8. Level washer (use a torpedo level, or the like) - you want door to
9. Try it out.
The only problems will be if the water line is in a different
location, or the like. Determine this first. Similar considerations
for the electricity, but there should be some play in the cable.
Not a lot to it. If all goes well, and you don't have a last minute
run to the hardware store, should be less than an hour, start to
finish. If you can get the old washer pulled out first, they will
likely take it away for a modest fee, otherwise you have to dispose of
the old one, which is a PITA.