you have the same oddball as mine. you either lift the rear like crazy ( lift the frame not the engine/wheel ) so the head point upward and clear the bar, or way better, you remove the engine from there.
maybe you could try removing the engine mount bolt and pull the engine backward a bit so you clear that damn bar. you usually have enought wire to do that but watch that carefully.
personally i pull out the engine. even tho its a bigger job its way easier to work on. i have to remove my caliper because i have rear disc brake and the brake line isnt long enought to just move the engine a bit. ITS WORTH REMOVING THE ENGINE !
Nightmare done ( no more 2009 maverick viron ). 2020 Scootterre Bistro 50 ( taotao atm50 rebadge and different front look ) in rebuild ( fairings only ) bone stock everywhere untill i know it runs good for at least 2k km.