This is how I did mine. Works relatively well and simple. If you have an ice wyvern with low dmg and pumped stamina this can work:

1- make sure the surrounding area is isolated around the acro you wish to tame.

2- Stop a short distance from the acro within ice breath’s distance.

3- ice breath the acro repeatedly

4- acro will switch to defensive, then do the loud roar if it takes enough dmg (watchout for the low roar, it’s a bait roar)

5- while it does the load roar, run up the top of your ice wyvern’s neck to force-feed the acro narcotics (I used bio toxin)

6- repeat until it knocks out

Continue to watch your back so you don’t end up backing up against anything or any other animals that could possibly interfere with the process.

P.S.- as of it’s new release, trapping the acro does not work at the moment. It’s taming mechanic will not trigger if trapped.

Hope this helps!