I used to creep up to about 21psi between 5-6000 RPM with a straight hose from the turbo outlet nipple to the wastegate actuator. After mildly porting the wastegate, my creep is down to about 17psi at 7300rpm. I can live with that.
First, remove the circlip attaching the wastegate actuator rod to the flapper arm.
For my VF34, the flapper door is 1.221" in diameter. The non-modified wastegate hole diameter is .986". Assuming I wanted to keep a .050" lip for the flapper door to sit on and seal, that gave me .134" to work with.
Remove the 10mm nut securing the clamp, then remove the clamp securing the exhuast housing.
Instead of allowing the exhaust housing to fall, I tapped around it lightly until I could slightly move it with my hand, then gently wiggled it off the rest of the way. You don't want the housing to touch the blades on the turbine wheel.
No need to worry about marking the exhaust housing or center section before you remove the exhaust housing - there is a small roll pin in the bottom of the center section to align the exhaust housing when you re-install it.