Let me give you some directions with better illustrations than you may have.
First, drain the cooling system.
Disconnect the heater hose from the thermostat housing.
Disconnect the 2 temperature sensor connectors from the thermostat housing.
Disconnect the upper radiator hose from the housing.
Remove the 2 thermostat bolts and pull thermostat housing off.
Remove the thermostat from the housing.
Do not become concerned if the thermostat tabs are not flush with the housing. This is normal and they will press into the housing when installed against the head. Install the thermostat into the water outlet connection:
Press the housing by hand.
Align the thermostat tabs into the recessed areas on the housing.
Reverse removal instructions for reassembly.
Fill cooling system.
I would suggest using new hose clamps. Any spring clamp should be replaced. be careful with plastic parts as they do become brittle as they age and will crack.