This is easier then you might think, which is why i'm writing this guide.
The easiest level for this is (imo) the one before stealth knack gets introduced,
Stage 4-2 "Some Disassembly Required"I got it on my second attempt without any skill and while half asleep
Tips:1. Use a version of knack with a strong attack (brittle knack is fine as you cant take a hit anyway) one shotting bots really is a bonus.
Dont use vampire knack which I shouldn't need to explain 2. Don't fight everything, if there are guards in a lit area then don't go there unless there is a bot in it (hover bots don't have lenses). There are only 2(?) fights with more then 2 enemies that are must fights, the rest you can take another route.
3. Save your super moves for said fights... I used a ranged attack on the 4 guys guarding the gate right before the end and another ranged attack on the guys surrounding Elvis. You may need to manually finish off any survivors.
4. Hover bots tend not to follow you, so run away rather then take the risk.
5. When approaching a bot in a lit area, use your ninja skills to stalk him and enter the light from the closest shadow and you can run in and hit him before he attacks. Paired with tip 1 and 4 makes for some hit and run fun.
6. Avoid the search lights for the additional achievement.
The Professional Intruder trophy in Knack worth 26 pointsCollected the clear crystals in Chapter 4-2 without being detected by the security robots