Changing a bar sink drain is a fairly simple project and many DIY home makers would have done this job at one time or another in their endeavors to improve the home. That is why there is no need for a professional this is a basic and easy project to do , one thing i always recommend is to have all items and equipment ready so there is more time working and less time looking. There's nothing worse than having to look for tools and items while working on a project, so in order to save your precious time , please do make sure preparation is first and foremost.
Once you have pre-cut your hole, ad a generous amount of plumbers putty around the hole in the basin of the bar sink. This will stop any suspecting leaks that may form around the basin. Carefully set the bar sink basket into the pre-cut hole in the sink basin. In your drain kit there should be a flat black washer, place this on the bottom of the basket and from the bottom side of the sink carefully thread on the brass nut, once this nut is secured, this will lock the sink and the basket together.
At the bottom of the bar sink , you will need to set the drain tailpiece and proceed to screw in the slip nut, this will connect the drain to the basket. Using a plumbers wrench carefully tighten the slip nut all the way. There is a part called a P-trap you will need to slip the end of the drain tailpiece into this. Then simply tighten the slip nut to the P-trap thus securing the two together. And use a plumbers wrench and carefully tighten all the way. Never over tighten screws or nuts , you may end up tearing the threads inside and can be costly to fix.
Place and set the P-trap into the wall tube or to the curved end of the wall tube. And once again tighten the slip nut, and this will lock the two into place. It is crucial that the tapered end of the slip nut washer is facing towards the P-trap. Place one end into the pipe that's in the wall and finally tighten and secure your slip nut, this will secure the bar sink drain system to the wall and plumbing ,let everything set over night. In the morning test out your work, turn on the water supply and look for any suspecting leaks and if everything looks OK then job well done!