How to trim a cut leaf Philodentron

I have a large cut leaf Philodendron that is growing year round outside and is getting too large. How do I trim it down?

Maybe there's a reason the biological name is Monstera deliciosa. In favored conditions, grows 60 feet tall, flowers, and has edible fruit (when fully ripe).

Unless you can control all the places it has found water, trying to control its size will only motivate root development and then it will redouble its efforts.

My neighbor a few doors down has given up on controlling hers. It has passed up a younger Carrotwood tree in size, and will probably outsize her Magnolia tree in 5 years.

Grinding the stump is futile. For the same or less cost, have someone pull it out with a backhoe or mini-excavator.

Well that seems a bit extreme. If you just want to 'trim' the Philodendron, pretty much cut off what you don't really want. Also not sure if it is indoors or outside.
I assume yours has a main trunk or perhaps a few trunks. You did not say how large it is now, or how big you would like it to be when you are done 'trimming'. Example, if it is say 6' tall you could easily cut it back to 3' if you want, it should send out new growth from below. Usuallay where there is a leaf, there is a growth eye. They are usually pretty forgiving if you don't cut off all of the foliage. It would help if we knew more.

Almost forgot to mention, if you want, you can probably root the top pieces you cut off if they are not too big, and if they have the air roots so much the better, if you want more of them.

It is about 6 ft now and would like to cut it down about to 3 ft. and has 3 trunks. I would to have it shorter for it is right in front of some windows. New to the area and hod no idea that it would get this big this fast. Do not want to lose the plant want to make it shorter and more manageable.

Hmmmmmmmmmm almost read your mind.
I'm pretty sure everything will work out if you leave some foliage on the trunks. It should send out new growth shoots by those leaves, and probably lower down too. Things my not happen until the weather warms some, they grow faster in warm weather. After you get some new growth you can trim it back even more as that growth matures, if you like.
Also apply a plant food with some nitrogen as the higher number to promote better growth. The soil should be moist most of the time, but not soggy wet, I think you will be fine. If you trim it back in the future before it gets to six feet, it will not be such a drastic trim, just do it more often.