I have spent 15 years working as a graphic designer, but for personal reasons the last three years I’ve been working part-time at a software firm. Now I’d really like to get back to full-time work and secure a position at the company, but am unsure how to negotiate this with the head of department. How can I best propose a change in my current contract, without compromising the relationships I’ve developed at the firm? I’d also like to enter the conversation with some bargaining power.