Funnel Builder Pro is a combination of Opt-in Pages, Sales Pages, AeroCheckout (FunnelKit Checkout), OrderBump, UpStroke (One-Click Upsells), and Thank you pages.
So, you won't require individual plugins. Their functionality already exists inside Funnel Builder Pro.
1) On your existing sites, upload the Funnel Builder and Funnel Builder PRO with the license key.
2) You can use the existing upsell or bumps as it is currently or can import (clone) them into Funnel Builder if needed. Here are some videos to help you:
- Import a Checkout page from AeroCheckout to Funnel Builder
- Import an existing Upsell offer from Upstroke to Funnel Builder
3) Deactivate the AeroCheckout, UpStroke, UpStroke PowerPack, and Order Bump only.
4) Nothing will be changed in the menu and existing checkout and upsell pages will be there as it was earlier - don't worry about it.
5) Once you confirm all the things, you can delete the individual plugins from your site to have fewer plugins.
Let us know with the login access if you need any help while doing it.