How do I use a downloaded keyboard?

[ianrm2005]

I have only recently got an Xperia T and have been struggling to use the keyboard with my big fingers! A friend suggested I download one, which I have, but I don't know how to change to it from the default keyboard. I can't find any settings that might allow me to change it, and it doesn't appear on my Apps page.

Any help would be gratefully received! Thanks very much,

[Uliwooly]

you could open the messaging app > tap on the input box > drag down the notification bar > keyboard

or

settings > language & input > you should be able to see the other keyboard.