You'll want to update the Marrilpack from the Curse Voice launcher by clicking the Update Now button that appears on the icon. You may have to close Curse Voice for it first before it will reappear. If you don't yet have the Marrilpack installed, you can search for it under Browse All Modpacks and install it from there. If Curse Voice doesn't work for you (unfortunately its Mac support is very limited), you can manually download the files you need from the project page on CurseForge.
In order to connect to the Marrilcraft Pixelmon server, you will need to have Marrilpack 0.4.0 installed and will need to manually download Pixelmon 4.1.4 and put it in the mods/ folder of your instance. You also have to be whitelisted, which means being a $10/mo Patron for at least one month — and having your pledge be processed (which usually happens in the first few days of the new month).
Enchanting Plus was removed due to an XP exploit and Iron Chests will be removed in the future for compatibility with SpongeForge, so players are encouraged to switch to the BetterChest mod's Adjustable Chests instead, which are actually a lot cheaper than Diamond Chests anyway.
If you run a Marrilpack + Pixelmon server, I can't necessarily troubleshoot any problems you have with upgrading, but just be sure to make backups before upgrading and know that sometimes it can be a little tricky when dealing with removing mods. Breaking all Enchanting Plus tables is a good idea first, but even the update to Pixelmon caused some problems with removing fossils, so it's a problem anytime a modpack updates.
Anyway, unfortunately my plans to update to a new server did not work very well — the host I had bought a server from did not have Java 8, a requirement for Pixelmon, so it was basically a waste of money. :/ Hopefully the existing server will be able to keep up and the lag will be minimal, but I will still be looking into other options for the future.
That being said, if you run into any problems on the Marrilcraft Pixelmon server or the upgrade process, please let me know and I will see what I can do to help! And for those of you waiting, make sure e-mail notifications are turned on and that you watch for instructions in the next few days so you can get your rewards from me, whatever they may be! (And for those of you who are not yet Patrons... hi!)
Have a nice day!