I received my kit today, and since I have been at home with 7 broken ribs for the last 4.5 weeks, I had nothing else to do except work on installing the kit.
For background, I had never even held a 10/22 before I bought a brand new one a couple of months ago in anticipation of the Marauder kit. I am not a gun noob however, as I have been shooting since 10 years of age (I am now 51), and have about 30 firearms in my collection including 12.5 and 12.6 prohibited guns. I just never got around to shooting a 10/22 as I had other .22's to use. I still have not shot my new 10/22.
On with the kit. I watched a few UTube vids to learn how to install the extended mag release and auto bolt release included with the kit. It was child's play for those who were wondering, although my 10/22 pins required a punch and hammer to remove instead of falling out like in the videos.
Next I went to remove the front and rear sights off of my rifle. I used a brass punch as suggested, and I managed to get the front sight off without damaging it, but my brass punch was no longer pristine. In other words, it bent.

On to the rear sight. I completely destroyed my brass punch trying to drive that sight out of the dovetail. On to a steel punch. Several hefty raps and out it came. The sight is prefectly fine by the way, and so is my steel punch.
Then the fun began. The fit of the 10/22 receiver into the Marauder lower is TIGHT to put it mildly. I have been pounding it with a rubber mallet, and even resorted to a steel hammer (using a block of wood), with only moderate success. The receiver is ALMOST home, but not quite. I know this because the "upper" from the kit will not completely touch the lower when I install it, with a gap separating them. The "upper" is a tight fit on the receiver as well, requiring a rubber hammer to drive it home.
That is where I sit at the moment. As mentioned, I have 7 broken ribs, so I can only fart around with it for a bit before I must take a break. I am sure I will get the kit installed eventually, but it is certainly not "drop in" in my case.