Replace the tables with impdb datapump which is already present in schema
Create a directory dbbackup1 where your dump file is placed for import operation.
create directory dbbackup1 as 'D:\dumpfile';
Grant read, write permission on directory to scott user:
grant read, write on directory dbbackup1 to Scott;
Import the table which is already exists in the database with the replace option of TABLE_EXISTS_ACTION parameter otherwise import process will generate the error that table is already exists in the database.
impdp directory=dbbackup1 dumpfile=SCOTT_DUMP.DMP logfile=SCOTT_DUMP_IMP.log