Yes, the pedals and saddles are easy to replace if you prefer a different style. Any standard pedals can be mounted on your VanMoof bike using the included wrench. 
Bikes released before the VanMoof S3 & X3 will fit any saddle which uses the standard 2-rail system. 
The VanMoof S3 & X3 use a one-piece saddle and seatpost assembly – if you want to change the saddle, you will have to install a new 34mm diameter seatpost as well.