According to the Liverpool Echo, the builder arrived at the event at the Sir Thomas Hotel in Liverpool in a wheelbarrow, pushed by Ricky Tomlinson.
Ex-housemates, including last year's winner Rachel Rice, Marco Marconi, Anthony Hutton and Pete Bennett, dressed in hard hats and high-visibility jackets as a tribute to Craig.
The book, entitled My Story: Building Beyond Big Brother, talks about expanding on his trade as a builder as well as his work on various TV shows following his time in the house.
He said: "When I first came out of the house, so many people asked me about doing a book.
"I felt I didn't have enough to talk about until now... I've done over 800 TV shows, been around the world, got my own production company - I've got this wonderful honour of being successful in my own right," he told What's On TV.
He revealed that the key to his success was that he had a trade before Big Brother.
"It helps to have something to offer the industry," he said, and also cited "hard work and honesty" as reasons for his continued success.