How to combine PI_Root with 24 GB filesystem?

Hello I have Ubuntu Mate installed on a 32 GB SD card on a raspberry pi 3 and currently have a 8 GB Ext4 partition labeled PI_ROOT and a 24 GB FAT partition labeled Filesystem and was wondering how to combine them so I only have one. I also have a 67 MB FAT partition labeled PI_BOOT but I think I do not need to edit that one.
-Thanks

Sounds like you didn’t expand the root filesystem at the initialisation.
Which version did you load?

Try reading the release notes, it used to be explained there