Modify text nest in multiple blocks

I have a drawing which includes several hundred blocks, all of unique names, which all have text nested within them.

As the drawing stands, the text style is wrong for every single text entity nested in the blocks. I want to change the text style, for the nested text, for every single block -from the wrong style, to the right style.

Is there any way I can select all the nested text and change it?

Editing the text options for every block will take me till xmas 2015.

Is there a Textstyle equivalent of LAYTRANS, where you can map one text style to a new text style, rather than one layer to a new layer?

Any suggestions would be welcome!!

Yeeeeeehaaaaawww!!!!!!!!!!!!!!

Thankyou Angel of CAD guidance.

txtmrg.dvb I love you!!