iI just put 4 to shields and 2 to engines, approach carefully up to the edge of the trespass line (red border) and stand there a bit. Locate the target comms antenna, and plan the fastest rout to there. If the rout needs some SRV jumping put engines 4, shields 2. Then rush to the objective, stand when within 50 meters, go to turret vision and scan it. If you do it fast usually the defenses get alerted after the scan. Then I always have 4 to engines and "fly" to my ship. And I say fly because if you run and its low gravity (almost always) you will tumble most of the time. Try to sprint -> jump towards your ship and then keep pressing the jump button.
Some side notes:
1) Now even if you don't make it, if the Srv is destroyed you auto appear into your ship. SRV costs about 5K, and these missions are very rewarding in cash (if allied with the faction who gives it it may pay up to 2 million
2) As I said try to go carefully towards the trespass zone. Main reason is to not take damage from needless tumbling. You want to be at 100% hull when the security start hunting you. If you have taken considerable damage, then go to synthesise (right hand panel) and select repair SRV.
3) If you really want the SRV you can Synthesise boosted hull for it. You need to have the appropriate materials though.
4) If you see many security ships flying around, and your vessel does not have strong drives and/or shields, dismiss it before scanning the data link. Just accept the loss of the SRV. Because these ships will start firing as soon as you board back to your ship. And if you can't boost fast enough or have your shields hold some firepower for a while, you might get in troubles far greater than the loss of an SRV.
5) Sometimes the target will be atop a building. Don't be confused. The SRV can fly up to very high levels with persistent jumping and 4 pips to engines. If the target is high but within 50 meters when you are on the ground you can scan it from there.