1) Alter 2) Balance the proportions 3) Change 4) Introduce regularity 5) Make symmetric 6) Make symmetrical 7) Modify 8) Symmetrise 9) To make or become symmetric 10) To reduce to symmetry 1) Symmetrise 
• (v. t.) To make proportional in its parts; to reduce to symmetry.
Sym'me·trize transitive verb [ imperfect & past participle Symmetrized ; present participle & verbal noun Symmetrizing .] [ Confer French symétriser .] To make proportional in its parts; to reduce to symmetry. Burke. 
[v] - make symmetric
to reduce to symmetry; make symmetrical.