IMHO check your friendly local or on line real 3d printing store. Microcenter may carry them .And then there is amazon and ali express, e bay etc.
Here is an option
https://www.printedsolid.com/collection … nector-ptc
https://www.printedsolid.com/products/m … nector-ptc
also quality tubing can help as they are made to tighter tolerances. Capricorn is the quality go to brand
also available from printed solid and other vendors.
https://www.amazon.com/Capricorn-Fittin … &psc=1
Options direct from Capricorn
https://www.captubes.com/shop/#!/Fittin … ort=normal
You may need to shop around a bit as there are many options out there.
As far as access to inside your extruder module do not know you may need to take things apart and may break something in the progress . use caution think things through and weigh the risks. Sometimes to know how a thing is assembled you need to take it apart. That is unless your are lucky enough to have access to an illustrated pars breakdown /exploded view.
good luck
Soliddoodle 4 stock w glass bed------Folger Tech Prusa 2020 upgraded to and titan /aero extruder mirror bed
FT5 with titan/ E3D Aero------MP mini select w glass bed
MP Utimate maker pro-W bondtech extruder
Marlin/Repetier Host/ Slic3r and Cura