TGB Key West tire repair and upgrades?

[FloridaRider]

Hey everyone so this is my first post as I found this forum while searching the web. I have a 2009 key west and I need to get a new rear tire for it. I believe it's a 120/90-10 tire I need to get, so could I just use one that I buy online? (Shinko sr426 tire) and then also to save some money I was thinking about changing the tire myself, would I be able to do it with basic tools or is that something I should get done in shop?

Then I would also like to unrestrict it, I read that I need to take apart a few things, what tools would I need to do that? Again I only have some basic tools

Thanks again and I appreciate any help or advice!

[harry]

you will need a electric or air impact wrench 
to de restrict the variator .

any tire the same size will do  its your choice to put on
a good one or a cheap one.

i would say take it to a shop since you don't have any experience
or the right tools. you need more than a bike tire iron or screwdriver.
to remove a tire from the rim.

oilyhans