well, shrinking the log can be acheived by using DBCC SHRINKFILE(logfilename, size). (depending upon how much space is currently being used, you will be able to shrink it to any size.)
by executing the DBCC SQLPERF(LOGSPACE) command you can see how much space is filled up and therefore to what extent you are able to shrink it.
by backing up the t-log you will release any data that has been commited, which will allow you to shrink the file to a smaller size. (if it doesnt release the space, just let me know, and we can see what is preventing it from doing so.)
you can also use the truncate_only option, though it will affect your capacity to recover the database.
I would advise regular t-log backups, this will help to keep the size of the log file down, while giving you the capacity to recover to any point in time in case of an emergency.
that being said, depending upon your recoverability requirements, you may wish to switch to simple recovery mode. (which will immediately free up all commited data in the t-log and only keep data in the log until a transaction completes, then it will be removed) this usually significantly reduces the amount of space that is being utilized by the t-log. (though not the actual file size, you will still need to shrink it.)