How to make adjustable part in Solid Edge?

What do you mean by "adjustable" ?
A flexible part that would act as if it was real, or a part that you can adjust by changing it's dimensions?

In both cases you need to make some change within the part, the main obstacle being the fact that both SolidEdge and SolidWorks build 3D parts as infinitely rigid, solid, non-flexible bodies. In SW, you can get some sort of "flexibility" if you create the new part within the assembly (in context, top down modeling) where the new part you build (spring, rubber or similar) is defined in between two movable existing parts within the assembly. As the distance or position of the defining two parts is changing, so will change the size/dimension definition of the inserted new part that is related to the parts that define ending surface(s)/points of the newly created part within the assembly. Creating a new part without an existing context (assembly) will define the new part without references in the assembly where you want to insert them, and therefore, the new part will act as if it was a solid body with infinite rigidity.

If you don't understand my explanation, I can translate it/explain in plain "pričaj srpski da te ceo svet razume" LOL :)

Hmm...is there any part of 300 pages included?
:))) Uzdravlje batice

In part, tab tools, icon Adjustable Part, in windows Adjustable Part click icon Variable table. selects the desired dimension. Close the windows variable table.
Your part is ajustable. When will you put it in an assembly, Solid Edge will ask how the position, in adjustable gold rigid. It will measure in assembly