Even with this method, we ended up with quite a few small bubbles in the vinyl.
The good news is that the bubbles were much less visible when the doors were upright, rather than laying down. But nonetheless, I wanted to remove as many bubbles as I could before installing the doors on the bookshelf.
The easiest way to eliminate bubbles from vinyl is to use a very thin needle to poke a hole in each bubble…
…and then use a scraper tool {affiliate link} to smooth out the air.
With most of the bubbles removed, the only thing left to do was poke a hole in each vinyl door front to allow our knobs to be installed. By holding the doors up to the light, I was able to see through the vinyl to see where the predrilled hole in the doors was located. I used a screw to poke through the vinyl.