Switch to prazepam if it's available for tapering. Imo it's the best benzo for tapering, and an easy switch when ur coming from diazepam as it's an active metabolite of diazepam.
Anyway, to help you taper diazepam; you could get the 5mg diazepam tabs or the TEVA brand 10mg pills (that allow u to break them in 4 pieces) and taper 2,5mg at a time. I'd definitely NOT go cold turkey. This could be dangerous as it can cause tonic-clonic seizure..
If you can get prazepam, you can get the tablets and the liquid formulation. Start by taking about double the amount of diazepam you're currently taking, and u can easily taper 5mg at a time once u adjusted at first. When you get to 15ish mg it'll be a little harder, you could use the liquid formulation to taper this if you like to take it slow. As 1 drop = 1mg, which makes it ideal for tapering the final bits. Imo prazepam should be the golden standard for tapering instead of diazepam. Underrated benzo IMO, and not very widely used either unfortunately.