This is a simple and fairly quick Mod you can do.
First unscrew the bolts from the back of the air Can. You need a T25 for this.
Then once the you have the can off remove the Coupling from the carburetor since you will replace it.
Now you would hope both sides of the pipe are the same size but the pipe downsizes different sizes on each side. So go ahead and cut your preffered length but I would suggest you cut it here. Make sure you use the side with the stem for the vacuum line.
Filter size for the 150cc cut is 50mm
Filter size for the 50cc is 42mm
****always double check your pipe diameter before you order
****it’s also possible to use your stock filter with a lite effort.
Put the pipe on first then the carb as it’s easier to fit on the carb than the intake. If you cut the length right and all you shouldn’t need a bracket. The length and carb are held on nice and tight and isn’t too much weight.
Also a good time to Upgrade to a better filter such as a UNI
All said and done you should have this. Enjoy.