Upgrade plugins

Hi i want to upgrade my eshop from 3.8 to 3.9 and then to 4.0 i have 5 plugins in you how do i start? as i can understand i have to buy them all but for what version? for all?
have they got upgade script ? will they keep my site data?

can you tell me please how to move on?

thanks!

1. Download the new ZIP file for each plugin from our site.
2. Copy folder from ZIP file for nop 4.00 (all files) to your new nop  4.00 store.
3. Restart your site (nop 4.00).
4. Plugin will upgrade itself.

You needn't use nop 3.90 for upgrade.
Upgrade to nop 4.00 at once.

If you see the message "Expire license" write us, we'll send URL with 50% discount.