how to adjust clutch

You have to loosen the lock nut on the clutch lever then screw the clutch cable in clockwise to make it softer/looser, screwing it out ( counter-clockwise will make it tighter.
 
stock blaster clutches are tough to begin with, add in a cable that prolly needs cleaned and lubed and they get super tough.
remove the cable from both ends, with the bottom hanging down, i spray wd-40 into the upper end, numerous times until it runs out clean at the bottom, then tape a small funnel over the upper end and put some oil in it to allow it to run down thru,
working the cable back and forth during both of these procedures helps get it flowing