Due to the fact that the products were downloaded, I'll need to confer with our Managing Director before I can complete the switch for you. This will cause a delay and I don't have an exact time frame for when I have more information for you, but I'll let you know as soon as I do
Update: Hey, sorry for the delay. Upon closer examination, the products you've purchased appear to have been purchased back in 2015. I missed that in the original examination of your situation.
We will not be able to change the vB5 licences to vB4 free of charge as a result of this, unfortunately. The pricing for converting these licences are as follows: Advanced Post Thanks / Like (Lifetime): $22.50 Advanced User Tagging (Lifetime): $19.50 AJAX Threads (Lifetime): $14.95
Those prices assume you do not have another instance of vB5 running that you are using these products on. The products are valid for one forum only, so if you have an existing vB5 forum that you are running these products on, and want to run them on another vB4 forum, the price will be $15 higher ($5 per licence).
The Branding Free licences can be converted free of charge
If you wish to proceed, please feel free to send me a Private Message with your choice of licence terms (whether you wish to retain the vB5 licences or not) and your email address, so I can setup a PayPal invoice.