How long is a piece of string?   Only you can answer this question.  If your Chinese is good then it wont be hard.  Honestly what kind of answer would you like?  I thought it was easy but that doesn't mean you will.

Hi, Good question!

May I ask what you mean with advanced level though? 4, 5 or 6? I am up to level 4 and found it manageable. I am studying since a year and a half so the material was not too hard for me. I found practice with actual HSK questions very helpful, to get in the grind and especially get used to the time pressure you'll have. I did that for 3 months or so, most intensely in the two weeks before the test.

Here is an overview over what is expected in terms of vocabulary and what question types you can expect:

http://www.gurulu.com/en/hsk.aspx

Hope this helps.

Good luck!