Hi Romans,
From what I've read, those are extremely low doses. The duration of withdrawal can vary from a few days (with the help of your physician or detox) to (in extreme cases) weeks (trying to go it alone).
IMO, you shouldn't be doing this without the help of your doctor; s/he can advise you better and prescribe
temporary meds that can help ease you through this process.
How to Withdraw from Methadone
Doc