Picked up my 2nd 15-22 and want to install a StrikeFire red dot system. The unit sits low on the rail and out of the box would have to try and align it through the factory sights.
Removing them is the preferred option but want to know about the boresighting process, is this something that can be done on my own or should I go through a shop...Thanks

Bore sighting and zeroing are basic functions that can be performed by the user, no shop required. To boresight, remove the upper from the lower, and remove the bolt. Place the lower on the bags where it is supported and level. For the .22, start at 25 yards. Look at the target through the barrel. Then adjust the red dot so that the dot is on the same spot on the target as you were seeing through the barrel.

This will get you on paper. You will still need to fine tune to get a true zero.

Most gun shops sell a little laser shaped like a cartridge that fits into the chamber. Turn it on and align your sights so the dots merge. I've never had the need to use one (I use the old fashioned way) but it's another toy to play with. And you will still need to fine tune the zero as cyphertext said because the path of the bullet is not a straight path.

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If you have sights that are already zeroed, then why can't you just align the dot to your sights? If I'm reading this right, it's because the red dot sits too low? If that's the case, I'd recommend a riser to sit it properly. Then, your sights should line up properly in either the center of the red dot or lower 1/3rd of the glass. The height in which your red dot sits will also help your cheek weld.