RV Repair: suburban dynatrail furnace P30S, lp line, controller card

Question
I turn up the stat,the fan runs but never ignites the burner. I was told it sounds like the fan isn't running fast enough to operate the sail switch,it seems to blow fairly good to me.
He also said it may be the controller card. He wants to install a new furnace. What I am wondering,if I can remove the furnace (what are the steps to do so),and take it to a service center to see wht my problem is?

Answer
does it click when you first tuen it on trying to ignite.

i would need to know what kind of coach you have
but the basics
1.turn off you lp
2.turn on you stove burn off lp in system
3.remove the cover
4.take lp line off
5.unplug wiring
6.remove screws holding unit in
yes most can test it