The answer to the original question is "very carefully." I have done this on two different servers, using both fdisk (for hard partitions) and lvs resizing techniques (easier/safer). Obviously you are using LVM, and as an aside, I prefer my disk layout to all be one under / (meaning one LVM managed volume --
/dev/mapper/centos7-root -- I don't need the separate
/dev/mapper/centos7-home partition. I only feel that is needed if you need it to reside on different storage or foresee expanding /home ad infinitum, or I suppose your backup requirements were specialized.
At any rate, do a FULL backup before proceeding. Be aware if you mess up, you will crash your server.
https://linuxhandbook.com/resize-lvm-partition/