Exactly what Alche said.
Don't set SETA to 10x otherwise most of the time laser will recharge and ship wont be fixed. I've found 7x seta to be most optimal just for fixing the aran.
M7M (obvious:P) Docking computer, 20 marines minimum 2-3 stars general, Boarding pods, SETA, Jump Drive, Energy Cells, Hammer heavy torpedo + flail missiles (just to destroy any enemy on the way, expect fighters, Q's or Kha'ak ships. It depends on your fighting rank).
Once you find Aran in unfocussed jump areas:
1. Clear the area of any hostiles surrounding Aran
2. Approach Aran with M7M (you can't target it!)
3. Exit your ship, now eject SETA from your M7M and pick it up.
4. Return to ARAN (distance between your M7M and Aran).
5. SAVE! then CTRL+J and hold it for 10-20 minutes (the more you fix this way, the more money you save on fixing it, monitor your O2 status) the Aran will go hostile, but it wont move or attack you.
6. STAY VIGILANT! Enemies sometimes jump into the sector and fly to attack you. It happened to me twice and I had to reload.
7. Return to your ship, CTRL+C 5. Piracy>Board Nearest Ship : Aran> OK
8. As your ship doesn't have SETA, don't jump out of it to use SETA since this time accelerator messes with boarding (ive lost 6 marines because of seta, so there was another reload for me)
9. Press R>Personell and observe your troops status.
10. Once ship is under your control you can finally select it. Transfer jump drive + 5 ecells and transporter device into Aran. Dock your M7M into Aran (it's best when you have Docking Computer onboard).
11. Jump back to known space. Fix the Ship at Argon Prime shipyards (any will do but I find Argon Prime the safest place for such ship). Equip it with appropriate shields and upgrade cargo, speed, rudder.
12. Enjoy your 120 000 XL storage ship