Getting from 13% bodyfat to 9-10% bodyfat?

That takes dedication for sure. Very little, if any, alcohol (beer); lots of fresh fruits and veggies, lean proteins (fish, chicken) and all in the proper portions. You're also gonna need some high volume or high intensity training to burn off that fat. People do it everyday but it requires more dedication and hard work than most want to put into it (myself included). I know how to get it done, but I like a beer or two and a slice of pizza every now and then. It's the last 5-10 lbs that are the hardest to get off.

I am at 8%or 10-11% depending on the scale used.
All I do is eat healthy, have one beer (MAX) a day and workout 10 - 15 hours a week...

It really depends on your lean body build... for some people 13% body fat is really quite low, for others 9-10% might be more than they should carry...

Let's just assume that 13% is a bit more than you should carry. Think about how you train to start with. You need distance to burn sufficient mount of energy to allow you body to use up the energy stored (i.e. fat). Also, the more muscle mass you carry, the more calories you will need, so adding a small mount of muscles can have a quite drastic effect on body fat %.

I'm a firm believer in that it's not only what you eat, but also how and when. Make sure you skip anything that is empty calories (yes, that includes beer and wine... they may not be very high in calories, but they add no additional value by consuming them, expect they do taste good, but I digress). Also, reduce your evening meals. If think about it, you are much more active during the day than you are at night, so eat a larger breakfast, a larger lunch, and a very small dinner (pretty much the exact opposite of what most of us Americans do...). You also need to figure out what works for you in terms of a balance between carbs, proteins and fats. Personally, I can't eat a high volume of carbs or I get sluggish and add weight quickly... we all need carbs though, it the only energy source (i.e. fast energy) that the brain can use (hence you get sluggish, disoriented and may have difficulty talking when you bonk). Lean proteins and large volumes of veggies (the darker the green the better for you, kale, broccoli, etc.) Fruits can be surprisingly calorie packed, so be conscious of what you eat. You do need fats, so don't skip that. High quality olive oil, avocado and nuts in moderation will help you lose weight.

Almost the most important thing you should do is to keep a detailed log book. What did you eat, how did you feel afterwards (to determine what is the best mix of carbs/proteins/fats), how many calories did you take in and how many calories did you use up (so you will need to know your resting metabolic rate... then add your daily activities, work, training, etc.). Don't try to lose too fast. Shoot for 0.5 lbs per week (especially since you don't have that much to lose) and be aware of lean muscle mass so you can determine weight loss in relationship to body fat %. Trying to cut body fat quickly is usually not a very good idea if you are trying to maintain the lower % once you hit the goal.