Are you having problems with getting the Lorazepam prescribed? Is that why you want to get off fast? Generally we don't recommend fast tapers as it's likely to lead to very uncomfortable withdrawal symptoms.
Using one benzo to try and compensate for another is also not a good idea. Unless you're struggling with interdose withdrawal but then it's best to crossover to only one benzo. Have you used Clonazepam or other benzo's in the past? This might affect your taper and withdrawal.