"Except that the request is to make something inherently less safe. Presently the firearm can be safely unloaded while the firing pin is disabled, with the two position flag safety conversion back to 1898 design the gun will be cocked and loaded in an unsafe position in order to unload it. These are the inherent safety flaws of the Mauser design that were overcome through much consideration over the past 110 years. The superior design currently installed also allows for a lower scope mount which aids rapid target acquisition which can save a life and greatly reduces recoil as a lower mount allows for a better cheek weld."
The original Mauser safety is 3-position and is as it is for a very good set of reasons (and is every bit as safe as the Winchester, et al). However, it’s definitely not amenable to the use of optics. Therefore, conversions abound. That said, though, the original Mauser remains my strong favorite (and, as I pretty much never use a scope, for me it’s a non-issue).
Should you wish to convert back to the original Mauser safety, from the more common horizontal 3-position, you‘ll need a new bolt shroud and cocking piece. And yes, it won't be cheap (unless, of course, yours is a Mauser rifle having been previously converted to the Winchester design, in which case it'll be a relatively easy and inexpensive change).