WOW! Now I feel dumb! I thought you meant getting your horse "on the bridle" as in, in a headset... not the actual physical application of the bridle!!
Some horses hate having a bridle put on. Here are some tips:
- check the teeth and see if they need floating; if the bit is banging on un-floated teeth, it may hurt
- hold the bridle above the nose rather than above the ears, this way you can control the nose (like at 0:25 of this video, but instead of already having the headstall on, you would hold the rest of the headstall in your right hand
http://www.youtube.com/watch?v=QuXSp76hq9U ) Then keep a grip on his nose while you bring the bridle up and over the ears.
- Make sure you can touch his ears all over without putting a bridle on.
- Make sure the bit isn't too tight in his mouth, it might hurt while you bring the headstall up.
Hopefully this helped!