I have been using simple press for about a year, but just joined as a gold member. 

It says ———  Before you can install any Simple:Press plugins you first have to install the main Simple:Press plugin for WordPress itself which you candownload here. Once you have it installed you should check and make sure the basics are operational before installing the Simple:Press plugins. ———–

So does that mean I must reinstall the new version of simple press even though I already have simple press.

If so will that screw up al the posts on my current version of simple press?

I am currently using version 5.1.3