Kernel patching

Upgrading to a new kernel version is necessary from a security perspective but it inevitably introduces a new entry in Grub. You can remove those redundant entries by:

1. Launching "Synaptic Package Manager".
2. Searching for "Linux kernel image".
3. Check "Mark for complete removal" for the kernel versions you no longer need.
4. Click "Apply".

Update: There is a variation to my recommendation previously.