Cajvol94,
Use something like a credit card to remove outer shell. Remove the battery, just plugs in.
Remove the two tiny screws.
Then, the hard part.
Your will see at least six small rectangular slots that engage the male plastic fittings from the back case.
A very thin blade or small screwdriver can be used to disengage these fittings. Difficult, some prying necessary.
Then you can get to the circuit board and then follow on-line procedures to install the antenna fitting.
I took apart an old router with four 2.4G antennae, used the cable and connector of one of them and then used the antenna on the TP Link.
Works well, not sure of the range. I tape it onto a sharpened wood yardstick and stick it in the ground near me.
mikeg26