Retail kegerators will come with beer lines that seem too long and some owners will cut the excess length out of their beer line. But as soon as you shorten your beer line you will have a foaming problem. This is because the excess length is intentional - the line is long to help prevent foaming!
The beer line’s 3/16” ID is just the right size to gradually slow down the beer on the way to the faucet and 5’ is just about the right length to work with a beer tower. Kegerators with door mounted beer faucets should have 6’ of beer line because the faucet is not mounted as high above the keg as the faucet in a beer tower.
Replacing your beer line is a relatively easy exercise and you rarely have to remove your beer shank or beer tower from your kegerator. If your kegerator is the style with the beer tower on top, you will need to carefully pry off the tower top to get access to the inside of the tower. Inside you will find a short shank and nipple held in place with a nut. Loosen and then slide the nut off the shank then pull the shank assembly out of the front of the tower to get access to the top of the beer line.
And BTW, if you replace your beer line make sure you add a couple of feet extra. Although 5' is about the right length, going 7' or 8' will do a even better job of controlling beer foam.