Advice with letter to tribunal

Hello

I wish to change my appeal from oral to paper, i sent the form with the tick box to request a oral hearing back around 2 months ago. what do i need to do now to request a paper hearing?

I am also writing a written statement that sums up my reasons for appealing, which is basicaly that they used a 15 month old medical report, even tho i sumbmitted new evidence and reported a deteriotion in my condition.

should i sent my written statement to the tribunal before i request a oral hearing? also will the dwp be sent a copy of what i have written in my statement?