Thanks for the support. I will explain the Savvy rear bumper and things to do so that you can get it together.
First thing you want to do is take your studs that will be used in the rear of the bumper. There are 4 studs and two aluminum plates. You need to press the studs into the plate. I used a deep socket and my vice to press them in. I believe a hammer would work as well. Make sure to get them nice and flush.
Now these plates with the studs have to be fished through the inside of the bumper. There are two access holes to get them in there. If you got some plastic washers in your kit to thread onto the studs do that now.
If not, I suggest putting some two way tape or duck tape on them and then fishing the in. You will have difficulty keep them there if you don't use tape to keep them there. I also put some superglue on the holes where it meets the stud. This will help keep them there nice and tight. Now let the glue dry up The reason you want to do this is that when you are installing the bumper you will carefully wedge the bumper onto the frame and take care to not put the studed plates back into the bumper.
Next lets move onto the frame tie-ins. First start by removing your rear body mounts. Take the bolts and the rear rubber isolation out. Taking them out will give you more room to work on the frame tie-ins. Each tie-in has an opened face which has to face in body mount.
When you try to fit the frame tie-in you might have this problem.
This means that your frame tie-ins are too snug. You will have to grind off some material. I used my angle grinder to remove the surface here.
Work on them till you can slide them in. If they fit a bit snug you can use a block of wood to tap them in the rest of the way. Now that you are confident you can get them to fit you take them off so can paint them up and set them aside.
Back to the bumper stud. Now take the bumper with the stud brackets installed and press the bumper on. You might have to tap the bumper with a mallet to get it on. Try to to keep it going on level and work it on each side slowly. Doing this will ensure that your studs don't back out and fall into the bumper.
When you get the studs through the frame you I suggest putting the serrated nuts on and tightening them down. This way the studs snug up into the holes of the frame and won't come out very easily. Next you can take the nuts back out and time to install your frame tie ins. Slide your frame tie-ins on and then for added insurance I loosely threaded the nuts back onto the studs.
Each frame tie-in will require you to drill one hole into the frame. Take the time to mark the hole, and drill it out. I removed the frame tie in one more time and drilled my hole out on each side.
Bolting the frame tie-ins will be easy if you a plate in your hardware bag that has two nuts welded on. If not, you can install it without. First remove the two bolts that hold your muffler to the frame. This will give you some extra room you will need. You will need to use a box end wrench and some tape. I put just a little bit of masking tape against each nut and then fish the wrench into the frame. Then you can thread your bolts on so that they are snug. Now you can pull your wrench out.
The last bolts you will have to install is two carriage bolts on the bottom of the bumper that will tie into the frame tie-ins. When you get them installed this is what it should look like
Don't forget your rear bodymounts and your muffler bolts.