Pool noodles to extend the length of your arms and be very visible. Then find the balance point between where they will move away from it and where they don't. Go slow. Slower. Still slower. Stop as often as needed. Give them time to drift rather than chase them. Move the pool noodles slowly if at all as you walk with them....
I'd sure love to know how to do that! ...
It will get better as you learn to read how ready the chickens are to move at all and/or panic. And as they learn. Eventually, you can move them at a chicken stroll pace.
If they panic, start over, further away and slower.
And/or wait until later in the evening, when they are ready to go to roost amyway.