1998 Chevy Venture Van thermostat

Disconnect the negative battery cable.
Partially drain the cooling system into a suitable container, to a level below the thermostat.
Disconnect the radiator hose from the thermostat housing.
Unfasten the thermostat housing bolts.
Remove the housing. Note the installed position of the thermostat, then remove the thermostat and gasket.
Thoroughly clean the gasket mating surfaces.

We had the same problem. Is there a trick to getting the bolts out and will it come out, looks like the fuel rail might be in the way