Download MultiMC here: https://files.multimc.org/downloads/mmc-stable-win32.zip
Download the pack here: https://www.dropbox.com/s/ohfqclkrjvtvjtx/1.1-client-sanitized.zip?dl=0

Unzip MultiMC into a folder where you wish to keep it.
Launch MultiMC for the first time

Select your java version when prompted
Click on Accounts at the top right
Click Manage Accounts
Add your MC account
Close MultiMC

Open your MultiMC folder and then the Instances folder
Create a new folder for the pack.  I called mine BBR for the rest of these examples, but it's up to you
Unzip the pack into that folder, so that the structure looks like this:
multimc\instances\BBR\minecraft
multimc\instances\BBR\patches
multimc\instances\BBR\instance.cfg

Re-launch MultiMC
You can edit the memory you want to allocate by right-clicking on the pack, selecting Edit Instance, and then Settings on the left.
Find the pack, launch!