Adam, you are in a good position because you must have already developed a strong musicality from your piano playing experience. Methods for developing hand/finger motion techniques I beleive are similar between piano and guitar but there a still few a major differences. One is the sound. Unlike piano the sound you make on the guitar substantially depends on how exactly you produce the sound with your fingers. Guitar has a very rich paliter of timbres and sounds and there is no "right" guitar sound but one can produce a vast variety of sounds depending on how the strings are plucked, ranging from very ugly to very beautiful, from bright to dark, from sharp to mellow an so on. So the key thing is to experiment with different ways to pluck the strings at different positions along the soundboard, different angles, plucking depths, different nail shapes (or no nails at all), and find the sounds that appeal to you. Once you learned how to produce those sounds then you can train you muscles and hands with slow repetitive excersizes to automatically reproduce them. This process takes years but one needs a constant attention to the quality of sound when practicing.
Another difference compared to piano is that playing guitar tends to produce a lot of unwanted sounds (sting buzzing from insufficient left hand finger pressure, right or left hand fingers touching adjacent strings, touching strings by bare nails of right hand fingers, skweaks from left hand finger movements on lower wound strings etc.). Learning to avoid those bad sounds is a big challenge on the guitar, you have to constantly pay attention to minor details of your playing and to those bad sounds. Also, as opposed to piano, to play clean and avoid those sounds you need much higher, almost sub-mm precision of finger movements. Those sounds are easy to ignore and miss when you tend to play fast.
Once you get these two key things sorted out you can progress much faster, the rest is just getting enough hours of efficient and focused practice which is pretty similar to piano practicing. Of course I did not mention obvious things that you also need to learn like right posture, relaxation etc, I assume those are similar to piano or any other instrument. Also, good quality guitar with the sound to your taste and right guitar setup (like string action) is also very important.
Paulino Bernabe 'India' 2001
Takamine C136S 1976
Masaru Kohno No.6 1967
Mitsuru Tamura No.800 1972
Rokutaro Nakade 1967, 1962