How do I merge my /boot partition to be a part of the / partition?

Short answer: If it ain't broke, don't fix it.

Long answer: If you insist on fixing what ain't broke:

1. Open a Terminal window.
2. Type sudo mkdir /boot2
3. Type sudo cp -a /boot/* /boot2/
4. Type sudo umount /boot
5. Type sudo rmdir /boot
6. Type sudo mv /boot2 /boot
7. Edit /etc/fstab and comment out the line that defines the mount point for /boot.
8. Type sudo grub-install
9. Type sudo update-grub (if you're using a BIOS-based install, you'll also need to specify a device filename -- probably /dev/sda)
10. Optionally delete the /boot partition and resize the root (/) partition. See here for details on how to do this.

I have not tested this procedure! If I've forgotten something or if there's an unexpected error, your system will be rendered unbootable! Hence:

11. Please reconsider my "short answer," above.