Message encrypted with a LFSR based stream cipher
I will try to not directly answer your question, but this exercise is so simple that it gets hard to help you without doing that. 

You are going to use a symmetric cipher (One-Time Pad - OTP), thus your initial step is to compute your key. This is given by the execution of the LFSR as you described, until a key-stream of the length of the message is obtained. Then, simply apply the OTP decryption step (*) into your pair (key, ciphertext). 

(*) I hope you know what the OTP decryption step looks like! ;-)