How to convert a partitioned table to non partitioned table in Oracle 12c

I plan to range partition a table (Currently about 4 GB in size and growing at a rate of 2 GB per year) in oracle 12c in production expecting performance gains. However just in case it fails to meet performance expectations and later I need to convert it back to non-partitioned state what are the steps to be followed. Note that this table has foreign key references from and to - with few other tables. Has several indexes also. Assume the steps will be done by a DBA.