I think one important thing I'd add is that you have to Say HOW. That's where you get the marks.
The easiest thing to do is refer to productions. After all, productions are different readings.
I mean, to link this to reading, you can say, "In the X production of King Lear, from a feminist point of view, the staging of the character, Cordelia opposite of Lear, Gonerill and Regan in act 1, scene 1 demonstrates her will to oppose patriarch forces therefore Cordelia is valued as a symbol of power within a feminist audience. Lighting used as Cordelia speaks her monologue, "...You have begot me, bread me, loved me..." creates an image of Cordelia as pure, truthful, moral all of which is valued from a Christian perspective. Thus the character Cordelia is percieved and valued on different levels from different readings of King Lear."
Oh, btw... If you're going to use the words above (which I doubt) try to reword them... because that was just a whamy rush job. I'm sure it's dodgy. If you're gonna do feminist and Christian or any other perspective, research it well, so that you can use better terms and see how King Lear can be interpreted by a person from that view. I don't do Feminist or Christianity; this was off the top of my head.
Also, I've concentrated on the character of Cordelia, and that's only a small portion of the play. You should see the play as a whole...
If you don't want to use productions - well, if the quesiton doesn't specify for you to refer to productions (btw, in my trial, you had to refer to two productions. So be prepared with productions) state how you see King Lear on stage, (your own interpretation of the play) e.g. Staging, costuming, lighting, tone, gestures...etc and justify them by saying, "from a feminist point of view, the staging of Gonerill and Regan in Act __ Scene __ suggests... From a psychoanalytical point of view, this staging can be interpreted to be a.... thus different readings implies a reconsideration of the values within King Lear."
Remember to relate back to question and even use words from the rubrick. Hey, why not?
You can also refer to Context. i.e. Elizabethan context. Contemporary context or Post modern context. I mean, Context is good to use because of how it says, "every NEW reading" in the question.
So yeah... ^_^ hope I made sense...