The main point of this is to show that the installation is not "so hard" as everyone on the forums and reviews of this were saying. The trick is to use the box that it comes in to hold one end of the board so that you can align it and easily install it with only 1 person.
Took my temps at stock clock from around 60c+ to around 50c at full load. There are better coolers out there but for $40 I'm happy and have enough room to overclock to 4.5Ghz now.
As noted in the comments it is better to leave the screws out, align the screw holes in the motherboard with the heatsink by looking from above as you drop the board onto the heatsink, and then dropping your screws in.
The cleaning of the heatsink is as per Arctic Silver's instructions and no I would not trust it to be contaminant free even if I just peeled off the plastic. Since you should be cleaning your CPU anyway you might as well clean the heatsink while you are at it.
This has reached the #1 result on google when searching for scythe mugen install. I hope it helped with your installations!