What window is it you're tinting?
You can, as I suggested previously, to use soapy water spray to help the film slide. Seems obvious but it's critical you don't let it the film stick to it's self otherwise it's scrap.
You use a hairdryer to soften the tint and make it more workable. Work from the centre out holding the film off the window smothing on the film with a credit card or something similar. Use hairdryer to chase creases.
Beyond that it maybe if you still can't do it then it may be worth calling round pro's.

It's been a while, but I'd expect about 30-50 per window.