Hello Ari,
After you make the Ultimate partition
active, you will just need to do a Startup Repair at boot for it to install the boot mbr for that partition.
Startup Repair
Once you are able to boot into the Ultimate partition, you should be able to safely delete the Home partition. If the Home partition is to the left of the Ultimate partion instead of the right side of it, then I do not know if you will be able to extend the Ultimate into the deleted Home partition for one drive again without a 3rd partry disk management program or deleting all partitions and doing a clean install of Ultimate.
Disk Management - Delete and Extend
Hope this helps,
Shawn