Hi I have a new tricity 300 and would like to adjust the brake levers has anybody attempted this

Find the part number of your lever and see if it is used on any other Yamahas then see if an adjustable lever is available for one of those .

I’m not looking to adjust the lever span but to move the position off the levers but cannot seem to be able to get remove the plastic casings that cover the handlebars I think the Xmax 300 is the same /similar set up
Can the levers be moved on the bars or are they fixed in one position

Try the 2 Allen key bolts underneath assembly.

As Scooter says - you should be able to rotate the whole 'block' that the levers are part of, by loosening the clamping bolts?