wat i do is,
step1, flash Gen-Y dual boot android --> hardreset+format noviand
step2, flash to Gen-Y d2x wm6.1 sense.(dont format noviand or u will loose ur android files)

ur phone is ready switch between wm/android

noneed to flash using MTTY.
just place android system file inculding Haret.exe. after that change ur startup.txt

yes, im on this 1
http://forum.xda-developers.com/showthread.php?t=623048
flash this rom will automatic install android as well

but after 2weeks i find that my phone cant perform as daily usuage.
need to charge my phone every 3-4 hour
phone get extremly heat
when i boot to WM, it only come with very basic windows. i loose alot of fun.

i decide to flash to this rom
http://forum.xda-developers.com/showthread.php?t=590090
suprising i still have my android os to play around and i can keep with sense2.5

any on spb mobile shell b4?
need review

its better to learn urself,
it will never be fun to let ppl help u flash a rom