I'm sure you will be fine adjusting your own WDH. Check your TV's owners manual and confirm if it has any specific requirements when using a WDH (ie; front suspension, etc.).
The eaz-lift installation instructions are "ok" to use..., but the WDH link below may provide a little more insight on the adjustment process and what to watch for. After opening the link, the top potion of the page addresses a standard WDH such as yours, ignore the remaining text on the subject of "Dual Cam setup" (Posted by JBarca on 6/06/06).
Tilting the ball mount and/or changing the number of chain links "under tension" will address weight transfer requirements.., and moving the ball mount up/down will address TT leveling requirements. Also, it's ok on the round spring bar WDH's if the spring bar tail has a "slight" up/down attitude, sometimes it's difficult to get them "perfectly parallel" to the TT frame.