Hi Mike
I was new last year with a 7510 when I did my 50 hour.
Can I assume you have changed the oil in a car before?
Its the same thing, except you'll be changing 5 gallons, not 5 quarts.
1. Browse the manual
2. Buy the parts
3. Verify you have the right tools (~26mm wrench for the plug in the rear right wheel well)
4. Clean the tractor first
5. Have plenty of buckets/pans for catching used oils
6. If you have large pieces of cardboard, work on top of it, you will spill some fluids on the floor.
7. Give yourself all day - it should take about 4 hours.
Make notes as you go along on the poorly written manual / pictures. You won't be doing this again for at least 2 years.
Its not hard. Its just your first time.
Jazdale