For posterity's sake, here's my little project...
Starting shoes, Allen Edmonds Manhattan, a nice enough wholecut shoe originally in cognac color which I had tried to darken to saddle brown by applying the AE brown polish to, mixed in with some black... needless to say it caked and ended up looking pretty bad. Plus for work I have to wear black shoes so I figured WTH, instead of buying new black shoes, try to transform these ones.
Step 1 - Using deglazer and cloth, stripped off as much of the main color as possible... actually I think the pic below is of the original shoes but the stripped version didn't look much different, just duller.
Step 2 - Applied a generous coat of dye to both the upper, edges and actually the sole as well just for good measure. Left to dry overnight, then gave a quick buff, and repeated the process. Probably 3-4 times total. Also soaked the laces since they were dark brown.
Step 3 - Conditioned the leather generously and left a few minutes to soak in. then wiped off.
Step 4 - applied polish/wax and put near heater for a few minutes, then gently wiped and buffed with a brush.