In this video I use a console command to replace all the Steel blocks to Carbon Substrate on a CV creation. Reference information:
Command:
replaceblocks ID Material1 Material2
Example:
replaceblocks 1142 HullLargeBlocks PlasticLargeBlocks
Material | Platform | Block Group Name
-------------------------+----------+----------------------
Wood Blocks | BA | WoodBlocks
Concrete Blocks | BA | ConcreteBlocks
Armored Concrete Blocks | BA | ConcreteArmoredBlocks
Carbon Composite Blocks L | BA, CV | PlasticLargeBlocks
Steel Blocks L | BA, CV | HullLargeBlocks
Hardened Steel Blocks L | BA, CV | HullArmoredLargeBlocks
Combat Steel Blocks L | BA, CV | HullCombatLargeBlocks
Xeno Steel Blocks | BA, CV | AlienLargeBlocks
Alien Building Blocks | POI | AlienBlocks
Carbon Composite Blocks S | HV, SV | PlasticSmallBlocks
Steel Blocks S | HV, SV | HullSmallBlocks
Hardened Steel Blocks S | HV, SV | HullArmoredSmallBlocks
Combat Steel Blocks S | HV | HullCombatSmallBlocks