How to down grade 4.3.2 to 4.2.1

[bubuham]

Is anyone please show me how to downgrade the iphone 4 from 4.3.2 to 4.2.1 and jailbreak. Cuz the 4.3.2 can not install certain app from cydia due to version incompatible or somethings

[Simon]

You need 4.2.1 SHSH to downgrade

[bubuham]

I think i had the shsh saved last time but just dont know how to use it

[Simon]

You can check with tiny umbrella what SHSH you have

[i.Annie]

If you do have them after you check with TinyUmbrella, just start the TSS server and open iTunes, shift+restore to 4.2.1. Custom or stock firmware, up to you based on your unlocking needs. So long as you run the TSS server, that's how you utilize your SHSHs.