Fruit Steeping Question

Hey all. I want to add 5 lbs frozen blackberries to a hefeweizen secondary which will be a pail. Having never steeped anything in my life I obviously don't know what I am doing. Could someone tell me the process? Should I even steep the fruit or should I just transfer the beer onto thawed out berries? Help please and thank you.

Ice

I once put 5 lbs. of raspberries into a carboy with a wheat beer on secondary fermentation, the berries capped the beer built up co2 pressure and exploded quite violently and frequently ,not a good situation. next time I soaked the berries in vodka for several hrs"small amount ,just enough to hit all the berries" then I added some water and lightly simmered the vodka off it and strain then add desired amount of extract. I made the whole process up but it worked really good