If you’ve purchased a VPS from 20i, you can point an existing domain to it. You need to replace the A record of the domain name to the IP address of the VPS.
At 20i you’ll have two A records that should look similar to these:
domain.com -> A Record -> IP Address
*.domain.com -> A record -> IP Address
All you need to do is replace the default IP address with the VPS IP address:
domain.com -> A Record -> VPS IP Address
*.domain.com -> A record -> VPS IP Address
Allowing about an hour for propagation, the domain should then point to the VPS.