Porch project, can I cut already installed vinyl siding? If so how?

I'm planning to enclose my front porch this year. What I have is a covered front porch, roughly 6'x 11'.Two 6x6 posts holding up the gable porch roof, concrete pad base.The project itself is pretty basic, three wall panels of 2x4 frame construction, but here's my problem. The house has vinyl siding.And I know next to nothing about working around/with vinyl siding.I'm going to have to attach the ends of the two side enclosure walls to the house sheathing and that vinyl at least some of it is in the way.Can I cut a trough through the siding on the two sides to attach the porch walls to the house, or does whole sections have to be removed? Btw, the porch enclosure will be sided with vinyl too so I'll have to make sure I don't damage the existing siding. Any help would be appreciated, and thanks!

yes, you can, and must cut the vinyl siding. Its a tedious job, but simple. Once it is cut and the framing, sheathing, and vapor barrier from the porch wall is installed you will have to cap the exisiting siding with J channel. If you can install an inside corner it is a better look, but it all depends on the exisiting vinyl siding job. If they used J channel in the corners (and some contractors do) instead of inside corners, use J channel. Look at figure 29 of the installation manual for an inside corner appearance. The easiest way to cut the siding is to draw a straight vertical line where you are going to attach the walls, compensate for the thickness of the sheathing as well as the width of the inside corner. It has to be carefully done or the exisiting siding will have to be replaced if you cut too much. Once you have the line drawn take a framing square and cut into the vinyl with a sharp razor knife, it may take a few swipes of the knife to cut it, but when vinyl is cold (NY Weather) it will easily break and crack, so using a knife is your best option. I build sun porches and gazebo's for a living and one of the pictures attached as a source will show you what it is supposed to look like when the siding is correctly cut and installed. If you need further help, feel free to contact me.

Paladins - answer is the way to do it, but, I'll make it just a little more simple, especially if you are doing this in the cold
*use a blow-tourch to heat up the blade and it just slides right through* Just keep heating up the blade!