First, it's never a good idea to remove/replace parts hoping to hit the jack pot. It never works, and only cost you money that could've been spent on a mechanic.
If your thermostat housing has a bleeder screw on the very top of it, then it's a simple matter of loosening the screw until anti-freeze begins pouring out. (Make sure your reservoir is full, of course)
If there's no bleeder screw, then remove the cap on your surge tank. Start the car, put the heater controls on full hot, no A/C. Then use the throttle to rev your motor to at least 1,500 while you squeeze the upper radiator hose several times.
Allow your engine to run until the thermostat kicks open. You'll know when this is when your radiator fans turn on.
Now, there may be another potential problem. The way you worded your question, I'm assuming you had no heat before you replaced your thermostat.
If this is the case, and it was because you had air in your system (there could be other reasons), then you need to worry about how/why there was air in your system to begin with.
The best case would be you have a simple gasket leak that's allowing fluid to leak out, and air to leak in.
The absolute worst case would be you have a blown head gasket.
When you are bleeding the air out of your system, allow your engine to cool down completely after you're done.
Then remove the surge tank cap, place your heater controls on full hot, and rev your motor while watching for bubbles in your surge tank.
If you are consistently getting air bubbles, even after several attempts to bleed the system, then you have a blown head gasket. (Also watch for excessive white smoke from the tail pipe on cold start-ups)