First, you should make a backup of your files. Do not try to clone the disk without a backup. If your backup fails (which happens sometimes) you might loose all your files.
Second, I've looked in the Mushkin website and did not see any software, but don't worry about it much.
Third, I've checked MiniTool and it has a resize function. Right click on the large partition and hit resize. A new Windows pops up and you can move the slider to the left. Keep it under 450GB so it can fit in your new SSD. Then clone the old disk to the new one. After this is done, extend the partition of the SSD to it's full length. This is what I would have done.
Good luck, and when you install the program, be careful as it tries to install the McAfee program, just uncheck it's box during the install process.
There could be a program that can clone the disk and resize it automatically, but I am not familiar with any.