1. Firstly, when you remove your existing strings, you don’t want to scratch or damage the string retainer. (The string retainer is the black piece that holds the string in place)  So before you take off your existing strings, you should first cut them with string or wire cutters. You can do this with the neck assembled or disassembled – just make sure strings are loose if you keep the neck on. You can cut the strings either behind (towards tuners) or before (towards the guitar body) the string retainer. You then pull the straight strings through the string retainer and remove string pegs to remove strings from the bridge. DO NOT PULL CURLY STRING ENDS THAT WERE WRAPPED AROUND THE TUNING PEGS THROUGH THE STRING RETAINER,  OTHERWISE YOU MAY SCRATCH OR DAMAGE THE STRING RETAINER. 
2. Secondly, when you install new strings:
   1. We recommend your first secure the neck to the body, and take time to polish the frets or clean the fretboard if needed. Installing strings is very similar to installing on a normal guitar with the following additional two steps:
   2. We recommend installing one string at a time. When you insert the string ends (usually a ring or ball) into the bridge pin holes and put the bridge pins in place, make sure the strings are exiting the bridge in a straight line towards the bridge. If the strings come out at an angle, it may impact string spacing on the white bone saddle when you assemble the guitar. If the strings are spaced evenly at the saddle when you assemble the guitar after tuning, you’ve done it right. If they’re uneven, it’s an easy fix –  just remove the neck, pull out pins and reposition the strings so that they come out straight and evenly spaced on the saddle.
   3. After you’ve inserted the string end and secured the bridge pin, pass the string through the string retainer. Once you’ve passed it through the string retainer, you can then insert them through the hole in the post of the tuner and tighten the string. If you have a newer guitar with our locking tuners, make sure the tuner lock is loose so the string can pass through easily. We recommend wrapping the strings a single wrap, and pulling it tight, then tightening the locking knob clockwise on the back of the tuner – then you can tune to pitch. If you have non-locking tuners (like Grover), you’ll want a minimum of 3 wraps per string as you normally would on a traditional guitar tuner.

Summary: With strings loosened, cut the old strings before removing, and don’t pull curly string ends through the string retainer.  When installing new strings, first install the neck.  Make sure strings come out straight from bridge pin holes. For locking tuners: do one wrap, tighten the lock screw knob on the back, then tune to pitch.  For normal tuners (like Grover) get 3+ wraps before tuning to pitch – just like a normal guitar.