Thought I should reply to this one.
I recon that you mean "install" instead of "download" the second time you mention it?
The installation instructions was located in the documentation page at the link you have posted, but I have moved it into the left menu bar now so you shouldn't need to look for it as a sublink anymore.
Direct link to the installation section
Concerning MJPoly Tools now, the development of this tool has stopped a long time ago and Mikkel jans is now working on OMToolbox instead which also includes almost all of the tools in MJP as well as a bunch of new ones.
Anyhow, MJP has been well tested over the lest years and as far as it fits your needs, there is no reason for trying out OMT, but if you want more, I definitely recommend that you take a look...