It depends. You have to do a lot of link removal work and also upload the LINK DETOX disavow file to Google and then it is up to Google how long it takes. Please also monitor your backlinks to be sure that you will not receive new bad backlinks (ongoing Link Risk Management) and that you need new good links. Please note as well that it might be necessary to wait until the next Google Update.
However, with the new Link Detox Boost we will be able to speed up the process noticeably!