Due to the inherant dangers associated with microwave ovens of any type, I strongly recommend that you do not attempt this repair yourself.
The adjustment of these doors are critical, and if done improperly can result in serious injury to you, or your family from the radiation produced by the unit.
If the existing door has been damaged It would be best if you took it in for servicing or had a tech come out and do the repair.
In addition to the above concerns the instructions to do this repair are not available to the general public. Simply because it is a dangerous proposition to have a lay person attempt these repairs.
I am sure that this is not what you wanted to hear, but it is the only honest, and safe answer there is. I would appreciate it if you would honor the time I have put into researching, and answering your question by clicking on the accept button.
Best regards; The Home Smithy
Once you have clicked on the accept button, please be sure to leave positive feed back for me.