Either transcribe the instructions by hand (easy if there's no diagram or picture) or scan it and attach as a JPEG, GIF, PNG, or PDF file.
A warning: Nothing attracts criticism like a student who posts his assignment but does not explain the details of the what he needs help understanding, or post a version of his work so far.
Conversely, the Forum tends to lavish attention and assistance on those who do show their work and post a good deal of background and detail.
If you want to be in the second category, I recommend opening a new thread and loading up your first post with details about the course, the hardware you have to use, the assignment, and your progress so far.
If you literally have made zero progress and don't understand even the first thing about relay ladder logic and PLCs, take a measured hour to start reading the material behind the "Learn PLCs" link at PLCTalk.net. It's excellent fundamental brand-independent stuff.
Once you have a little bit of an idea about "here's what I don't know", post on the Forum.