If you wish to switch to buprenorphine, reduce as above (if necessary) until you hit 20 mg, then after 5 days of methadone 20mg, wait between 36 and 72 hours (the longer the better) until you are experiencing as severe a withdrawal as possible then switch to 16mg mg buprenorphine a day.

I have uploaded some guidelines for this transfer to the document section, which I suggest you consult, as if you do not wait sufficiently long, or try to transfer too soon you are liable to experience precipitated withdrawals, which are unpleasant. Stabilise on the buprenorphine 16mg for 5 days, and then cut back by 1mg a day until on 2mg, then 1.5mg, 1mg, 0.5mg, and then stop.

Depending on the pills you use this may necessitate dissolving a pill in some water, and measuring out doses with a syringe (i.e. dissolving an 8mg pill to make 8ml of solution. Then delivering a dose sublingually using the syringe).