Yes you can!
Just submit a ticket to gameserver billing with:
1. The MH number of the server you would like to split
2. The date on which you would like the split processed (please note that due to splitting being a manual process, if you want this done a long time in the future, we may ask you to submit another ticket at that time)
3. Any changes you would like to make to your comms server before it is split i.ie changing the number of slots.