The simple answer to this is yes or no! it all depends how your mechanics skills are.
If you are ok with dismantling the Husqvarna chainsaw and putting it back together then YES, it is fairly simple. All new replacement parts are cheap and easy to buy.
View or download the free Husqvarna 61 parts list from HERE, which will show you all the chainsaw parts in an exploded view diagram/schematic picture, along with all the different parts numbers.
First up check for any bits of wood and oil gunk, clean if so. Then check for any broken parts or obstructions to the brake mechanism. If all seems ok put back together and try it out.
Now if it still is not working or is stuck and you can see anything broken parts, take note of the parts identification numbers and order a new part from the various online Husqvarna parts sellers (there are hundreds at competitive prices).
For a better description of assembly and disassembly of your Husky chainsaw you can also find a full chainsaw service workshop manual from HERE, alternatively use the search button (magnifier icon) at the top of this page and grab yourself a manual using that, which helps a lot when working on your chainsaw (there is also a request a manual from the requests page HERE).
This information should help you in repairing a Husqvarna 61 chainsaw brake, if not just ask a more detailed question for free from this website. Good luck with your brake repairs!