Forum menu
This is the page I was following to speed up mine
http://www.howtogeek.com/164106/why-is-my-nexus-7-so-slow-8-ways-to-speed-it-up-again/
It included the TRIM process, but I couldn't get LagFix to work and ForeverGone seems to have forever gone from the marketplace, so I used Trimmer ( https://play.google.com/store/apps/details?id=com.fifthelement.trimmer&hl=en_GB). They all perfrom the same fstrim command under the covers.
The first page above links to the follwoing process for rooting which is what I followed, prior to TRIMing.
http://www.howtogeek.com/120482/how-to-root-the-nexus-7-galaxy-nexus-or-nexus-s/
The link for the rooting tool kit download on that page is dead, but it can be downloaded from http://www.wugfresh.com/nrt/
I'm no expert, this was my first attempt an rooting and I just followed the links and the pop-up help in the tool kit. Good luck and don't blame me if you brick it.
Yes it does wipe all your data at the unlocking step before rooting as a factory reset is done at this point. The process recommends you to do a back up and the tool kit can do that first. When I logged back in after the reset I deliberately didn't sign in with my google account to avoid it bring all my apps etc back, wanted to start with a clean slate. It is mostly just used for browsing anyway.