How to install leaked 2.1 on Cliq without rooting

[fineboi2009]

i reflashed it again but it has some contact sync issues i used sdv sumthn like dat under cloud from registration point so i can have ma contacts and its fast on launcher pro anything else is slow but that damn performance manager is always saying ma ram is low or sumthn i got a 2gb sd should i upgrade and cud u help me with this stupid force close for the text messaging it b nice to if i cud get that wireless tether

 

[cpdeepak]

I want to upgrade to the Official 2.1. Can I just overwrite it without downgrading to 1.5?