I did this not too long ago when I changed my data partition from FAT32 to NTFS, because I had unlimited file size in the shared data partition, I did not need the separate shared /home partition for all my Linux systems.
I kind of followed the tutorial in the link below, made a directory called "/newhome" and used the command suggested in the tutorial to move all files and links from the old /home to the newhome in the / partition. Then remove the line in /etc/fstab for the /home partition and remove directory /home. Re-boot and re-name /newhome to /home after verifying my user settings are good, you can also log in as root and delete the old user if it is no good and create a new user. You can then use a partition utility to delete the home partition and expand your / partition to take up the space.