Welcome! Learning how to rebuild you own regs (1st, 2nd stages...) is not rocket science, but it is regulator science. SurfLung is correct that most all of the schematics and repair manuals are provided free courtesy of VDH in the "manuals and catalogs" link at the bottom of the page. Info and schematics on the Kraken are also found there. Look them up by brand. I have dove with my Kraken since 2014 and absolutely love it. Like any other reg there are ports for a pressure gauge and for LP inflators.
There are a number of really good books out there that will give you a great background in the theory of how regs work - "Regulator Savvy" is a good one. Although I knew how regulators worked, I have zero formal training in regulator repair. It took me a few years and about 20 rebuilds to feel comfortable rebuilding diaphragm regs, piston regs, various second stages, etc... I still run into issues that leave me scratching my head and running to this forum for advice. Everyone here is really good about responding. Have fun with your projects, but do expect a learning curve as opposed to being able to just jump in and fix stuff. My 2psi. Mark
"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968)