How to enlarge the /boot space on the ubuntu_16.04_mate for Raspberry Pi

I am using the Raspberry pi with 16G microSD card. But the /boot space was only 64Mb. Enlarging the boot space is necessary.

1. Tools

1. Raspberry pi 3 b
2. 2 microSD card with ubuntu_16.04_mate installed
3. microSD card reader
4. The card running ubuntu: C1
5. The card to be enlarged: C2

2. On C1, install the Gparted

1. sudo apt-get install -y gparted
2. sudo gparted

3. On C2, enlarge the /boot

1. Unmount the PI_BOOT
2. Unmount the PI_ROOT
3. Resize the /ROOT to get unallocated space
4. Delte the PI_/BOOT space
5. Create the space

   Create as: Primary Partition

   File system: fat32

   Label: PI_BOOT

6. Copy the boot file from C1 to C2

7. sudo su

8. cd /
9. sudo cp -r boot/*.* /media/test/PI_BOOT
10. reboot