expand /boot partition help please

Here is my lsblk

lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 1.8T 0 disk
├─sda1 8:1 0 349.5M 0 part
├─sda2 8:2 0 5G 0 part
├─sda3 8:3 0 200M 0 part /boot
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 1.8T 0 part
├─VolGroup00-LogVol01 253:0 0 11.7G 0 lvm [SWAP]
├─VolGroup00-LogVol00 253:1 0 101G 0 lvm /
├─VolGroup00-LogVol02 253:2 0 20G 0 lvm /usr
├─VolGroup00-LogVol05 253:3 0 102G 0 lvm /home
├─VolGroup00-LogVol04 253:4 0 16G 0 lvm /var
└─VolGroup00-LogVol03 253:5 0 512M 0 lvm /tmp
sdb 8:16 0 19.3G 0 disk
sr0 11:0 1 1024M 0 rom

I need to expand the size of my /boot partition due to a kernel upgrade.

I have resized the LVMs using command line but I'm not sure how to resize /dev/sda3 which is /boot

or remove unused files:
boot]# ll
total 158020
-rw-r--r--. 1 root root 122059 May 5 2014 config-3.10.0-123.el7.x86_64
-rw-r--r-- 1 root root 137701 Feb 19 23:48 config-3.10.0-514.10.2.el7.x86_64
-rw-r--r-- 1 root root 137701 Mar 10 10:30 config-3.10.0-514.16.1.el7.x86_64
drwx------. 6 root root 4096 Apr 12 16:54 grub2
-rw-r--r--. 1 root root 15723655 Apr 1 2015 initramfs-0-rescue-95830f31d3db445aaf0ade5cde6bd352.img
-rw------- 1 root root 24194692 Mar 15 09:12 initramfs-3.10.0-123.el7.x86_64.img
-rw------- 1 root root 25201972 Mar 15 09:13 initramfs-3.10.0-514.10.2.el7.x86_64.img
-rw------- 1 root root 18507746 Mar 15 15:06 initramfs-3.10.0-514.10.2.el7.x86_64kdump.img
-rw------- 1 root root 24374722 Apr 12 16:54 initramfs-3.10.0-514.16.1.el7.x86_64.img
-rw------- 1 root root 18504904 Apr 29 09:22 initramfs-3.10.0-514.16.1.el7.x86_64kdump.img
-rw-r--r--. 1 root root 4438970 Mar 15 09:12 initrd-plymouth.img
-rw-r--r--. 1 root root 228562 May 5 2014 symvers-3.10.0-123.el7.x86_64.gz
-rw-r--r-- 1 root root 277969 Feb 19 23:51 symvers-3.10.0-514.10.2.el7.x86_64.gz
-rw-r--r-- 1 root root 277943 Mar 10 10:35 symvers-3.10.0-514.16.1.el7.x86_64.gz
-rw-------. 1 root root 2840084 May 5 2014 System.map-3.10.0-123.el7.x86_64
-rw------- 1 root root 3112473 Feb 19 23:48 System.map-3.10.0-514.10.2.el7.x86_64
-rw------- 1 root root 3113648 Mar 10 10:30 System.map-3.10.0-514.16.1.el7.x86_64
-rwxr-xr-x. 1 root root 4902000 Apr 1 2015 vmlinuz-0-rescue-95830f31d3db445aaf0ade5cde6bd352
-rwxr-xr-x. 1 root root 4902000 May 5 2014 vmlinuz-3.10.0-123.el7.x86_64
-rwxr-xr-x 1 root root 5391456 Feb 19 23:48 vmlinuz-3.10.0-514.10.2.el7.x86_64
-rwxr-xr-x 1 root root 5394272 Mar 10 10:30 vmlinuz-3.10.0-514.16.1.el7.x86_64

Thanks
cwc