I'm a DIY kind of guy, and I recently had some trouble with my fridge not cooling. I ended up taking the burner and piping out and apart, and cleaning the burner. When taking the tubing apart, there is actually probably only one or two fittings to be undone, as with most things the order is obvious after you've got it apart.
For gas tubing, you can test for leaks without lighting the burner by using a soap + water mixture sprayed around the fittings. A leak while the gas is on (remember that gas will only flow under specific circumstances, check your owners manual) will bubble the mixture and then you can tighten the connection.
As always, use appropriate safety gear, I'm not a propane specialist, your own risk, etc, etc, blah blah.
Here's a shot of the crufty burner next to a shot after a few minutes with some pb blaster and a small wire brush.
1995 Toyota 4Runner SR5 4WD 5 spd
2002 Eagle Summit 12