Though I have both Perlick and Nukatap, I find the Nuka's though perfectly functional, completely ugly...Perlicks just look so much nicer!
What part of changing lines is giving you issues?
A lot of folk get stuck at the shank wrench and try and use what they have on hand... that can get aggrivating... Most of the time I hate saying "spend more on this.." , but if you don't have a proper shank-wrench, it'd be money well-spent. Here's a couple:
https://www.brewhardware.com/product_p/kegtool.htmhttps://www.morebeer.com/products/komos-pro-draft-wrench-1.htmlYour tower looks like the standard ones, here's a couple pics that might help:
View attachment 840033
and use string or wire to hold up the inner nut, spacer and optional washer;
View attachment 840034
feed the lines out the front when you pull the shank out;
View attachment 840035
You can replace the line outside the tower and shove it back in.
If you use Bevlex 200, you probably just need the hose clamps to replace what's already there.
If you go duotight/EVABarrier (Highly recommended), you'll want new shanks;
https://www.brewhardware.com/product_p/shanksstowerpush.htmI hope I covered your issue..Please get back and let us know.