I drilled two holes on the new termostat. Im not shure if there is a spesific size & placement of the holes for better performance. But I just did it by eye. after drilling the holes I noticed that there where little metal shavings stuck to where I had drilled, so using a bigger drill bit, I smothed both sides of the holes. (dont want loose pieces of metal moving freely inside your engine.)
The way the system was designed, it dont need a housing gasket. Only a termostat gasket. So the housing is soposed to come out easily. Sometimes mechanics will add silicone between the housing & the engine, so if it gets hard to pull out. carfully use a flathead scredriver to prie it out.
For the placement of the termostat. Have one of the holes in the highest level posible, so that the air left inside the Lower Intake Manifold can come out .

another thing to remember is to clean the flat surfaces with a razorblade.
Now is time to reinstall the termostat housing & tight both screws. Then reinstall the vacume line, & the radiator hose if it was disconected.
Then go back to the radiator & reinstal the drain nipple & fill the radiator with coolant. (when my radiator was full, I pressed the top hose a couple of times, & the coolant went down.)
Leave the radiator cap open.

Open the valve on top of the termostat housing.

Notice I added a pice of towel to catch the fluid when it comes out.
Now turn the car on with the valve open & wait one or two minutes until coolant starts to come out. Close the valve, add more coolant to the radiator, & close it.
Now is time to wait for the car to reach normal operating temperature. When it does open & close the valve a couple of times to let the rest of the air out. turn off the car, Wait till it gets colder, & add coolant to the radiator. & the job is done.