Need Help computing diazepam for taper from 15 mg temazepam

I am finally ready to start my slow substitution withdrawal but am having quite a time computing the amounts.  Ashton uses 30 mg temazepam, but my current (9+ years) dose is only 15.  My brain will just not do the math.  Can someone help?  My temaz is in capsule form so fairly easily halved.  My diazepam pills are 5 mg but I do plan to get a scrip for 2 mg soon. 

The conversion from temazepam to diazepam looks to be 2 to 1, so 15mg temazepam would equate to 7.5mg of diazepam (1 1/2 of your 5mg pills).

Thanks.  My brain finally figured this out.