Purging old linux kernel versions

I now have 3 versions of linux kernel to choose from. 4.18.0-25, 5.0.0-23 and now 5.0.0-25, listed on grub menu.
I have limited disk resource for Zorin, as disk is small by modern standards and I dual-boot.
I have googled advice and seen on ubuntu forum that best method of removing old linux-image and linux-header versions is to use Synaptic PM, being careful what you select and double check what you select for removal. Like they say in bargain shops "when its gone, its gone" using this method. Also advice is to keep two most recent older versions as well as the current version.
There will be a time when I will want to remove 4.18. So is Synaptic the best way to do this tidy up task? (avoiding terminal command line).

Yes, Synaptic should be able to do this for you - just enter the exact search for 'kernel'. Next, click on the 'S' column so that all installed ones come to the top of the window together. Then select each element of that kernel, and right-click for 'remove':

I would like to add that I have done this, personally. Synaptic does, indeed, do a better job than anything else, including the command line.

Thanks for confirmation guys. I am more comfortable using Synaptic for this, as you can preselect, check selection, double-check selection then act. Boom!

Wow. Big update on Z15Core yesterday for me via softwarew updater. Linux kernel 5.0.0-27 etc.
Noticed oldest kernel version has gone as result, leaving three 5.0.0-23, 5.0.0-25 and 5.0.0-27 installed.
So in my case seems latest 3 are kept and anything older purged as part of the update. Suits me fine.

Also pleased to report that sound still works with 5.0.0-27, which was problem for me after initial update to 5.0.0-23.