Technically by RAW:
Roll required to beat Endurance (Endurance+5 to beat best roll, ignored for willing targets, like yourself)
Total Stress+1 Shift to "take out" character (plus stress for consequences if character chooses to resist, ignored for self)
Three shifts per point of refresh (to place aspect taggable for temporary power FP requirement) OR you can take consequences to satisfy this, gaining one tag per consequence.
So for a willing character with Good Endurance, you're looking at 5(four stress plus one)+2 (mild consequence)+3 (second aspect)=10 shifts for any two refresh power if you're willing to take a mild consequence. 11 shifts if you're not.
If you've got FP to burn, you can get away with not placing the aspects and spending one FP per point of Refresh instead. So a two refresh power would be 5 shifts plus two FP, or 8 shifts plus 1 FP, or 7 shifts plus a consequence and 1 FP.
Removing the aspects (including consequences) could conceivably remove the power, depending on the GM.