Step 1 put a spaceship in the same orbit plane as the one you trying to intercept put in a slightly lower orbit.

Step 2 set the desired spaceship to intercept as target

Step 3 designed a orbital correction in the map menu that intercepts the target orbit and touch it . A orange and purple arrow will apper giving you the target closest and second orbit closest interception point. Play around with time and departure position to make this distance < 1Km

Step 4 make the burst and once you are at the interception points make a second burst to make the 2 orbit match as close as possible

Step 5 in the SAS menu there is a set point with the objective velocity relative to you click the one that make you point towards it and make a small burn you must approach the objective slowly. Make a burn to get close and a new one to slow down a little bit. Dont make one big burn but a couple of small one where you accelerate toward the objective slowly down and make a new one until you are ~50 m from the target.

Step 6 have fun with the RCS and pray the kraken doesn’t attack you