i can't find any of the HK 51 parts can someone help me

The person best placed to help you in-game is ... you.

That said, here's some advice I've posted a few times before:

Unless your characters aren't high enough level to survive in the various places, you don't *need* help. (You need one at least level 50 to even get the missions, and one on the opposite faction that's high enough level to survive in front of the Dark Temple on DK or in the ruins of the Jedi Temple on Coruscant.)

 

Establish a grid pattern. With Sprint *ON*, advance seven foot-fall sounds (turn the audio up so you can hear them, obviously) each time along a straight line and scan each time you stop. At the edge of the areas, turn right or left (alternate!) and advance seven foot-falls to the next line over, turn again and proceed back along the new line.

 

If you find it, be polite and announce its location in /general chat *immediately* to help other people who might be searching. If someone else makes such an announcement, *immediately* go to where they announced because it will be available *there* to everyone for only one minute, then it will jump to a new hidden location which *might* be in the area you've already searched.

 

And that's all the help you need.

I'd also add two other points that came up once before:

* Take breaks for sure, but do it between planets, not during a planet.

* If you take a break during a planet, restart the planet from the beginning in case someone found it during your break (it moves to a new random location in the area that might be somewhere you already searched.)

* Don't use Group Finder to queue for anything (Flashpoints, Uprisings, Operations, Warzones or GSF, doesn't matter) while you do this.

* If you do queue for something and it pops, restart the planet from the beginning in case someone found the part while you weren't there.

Note that two of the parts are available from specific Flashpoints. Despite the various out-of-date guides that say you have to run them in Hard Mode (now called Master Mode), that isn't true any more - you can do them in Story mode and it's OK.

But, the part doesn't drop from the boss itself, but rather from a blue clickable thing that activates once the boss is dead.

i can't find any of the HK 51 parts can someone help me

Since you didn't give any details:

Do you have the quest?

Do you have the seismic scanner thingy? Is it in your inventory while you search?

Did you talk to the Jawa in Outlaw's Den on Tatooine to get a part and/or the 'thingy' (if I recall)?

Etc, etc.