Interpretation is a radical strategy for conserving an old text, which is thought too precious to repudiate, by revamping it.
The clause refers to old text, not to strategy
Imagine an old text which is historically important or has some interesting thoughts or is imaginative and beautiful. Imagine that at the same time it contains some thoughts that are now considered obsolete or false, or politically incorrect.
Imagine someone who wishes to publish a book about this text. He considers the text too precious to confront the text's authors in his book and say that such and such passages in the text were incorrect or inconsiderate, that such and such views were false.
Then this someone might subject this text to interpretation in such a way that will make it seem more modern, more compliant with today's standards, more interesting to today's readers. This interpretation will try to not to confront the text's inconsistencies but to hide them or reinterpret them in a way that will make them seem less important. This will in effect "revamp" the text but at the same time might change its real meaning.