How to you leave your job?

If you are feeling that frustrated with your current job then you should accept the job offer. Your boss should understand and wish you good luck with it, especially if you are friends. It is really easy to get into a rut and make excuses not to take a leap of faith and change jobs, but try to imagine where you will be in 2 years time if you don't take this new job. Explain to your current boss that its nothing personal, you just need a new challenge. Good luck, hope it works out for you.