I have a model No. 30500x92A I have tried to start the mower with a schooldriver and the starter only clicks. Where can I get a book to show me how to replace the starter?

Hi,
You did not state the engine brand, so the following link is for Briggs single cylinder L-head engines:
http://www.mymowerparts.com/pdf/Briggs%20&%20Stratton%20Service%20and%20Repair%20Manuals%20S pec%20Charts/270962%20Single%20Cylinder%20L-Head%20BRIGGS%20&%20STRATTON.pdf
Peace,
Clarke

Tecumshe 10 Horse power fomula XL/C

Hi,
Then try this link:
http://www.smallenginesuppliers.com/html/engine-specs/tecumseh/Tecumseh_L-Head_Engines_Service_Information.pdfIt is just four bolts that a #3 Phillips or a7/16" socket fits; two ar on each side; plus the wire from the solenoid, of course.
Peace,
Clarke

Do I need to take off the gas tank frist to get to the starter?

Hi,
Well I can bet the nut holding the wire from the starteris accessible, but I cannot say. If all four screws /bolts are visible without removal, then the starter will drop downward.
Peace,
Clarke