Degu are very friendly and curious pets, although they can be extremely skittish if they have not had much contact with humans. Like many pets they love routine, so taking the opportunity to talk to them in a calm, quiet voice as you feed them will get them used to your presence. They can be very food driven, so hand-feeding favourite treats can be a good way to get them associate you with positive things.
Let your Degu come to you, and don't chase them round the cage. You can begin by rewarding them with small treats for placing their front paws on your hand and build up to rewarding them when they are fully stood upon your hand. Then you can pick them up, keeping them sheltered, as many Degu will want to jump from you regardless of height.
Degu are highly intelligent and can be trained, through toilet-tube training to let them be picked up, and becoming used to the sound of your voice and some commands.
Regular, short sessions of handling are best. Degu may enjoy free-roaming but are very destructive, so ensure you do this in a safe space where you do not mind if furnishings or skirting boards are chewed. To recapture, you may need to be very patient to allow them to come back to you.