What are the steps for decryption of RC4?
Your guess is correct. RC4 basically generates a very long key to fit your message. Encryption and decryption is simply xoring with the output of RC4 for that particular position in the key stream.

In general, most stream ciphers work that way. The complex part is that the algorithm should generate a very long key that is not susceptible to attack (the ideal being a one-time pad of the same length as the message).

So once you understand encryption using RC4, switch "plaintext" and "ciphertext" in the explanation to give you decryption.

edit: you probably know this already but it doesn't hurt to reiterate: don't use RC4.  It is not secure and can be broken.