Changing extents in table, in prod.

Hi, I am a 'learning' DBA just starting to figure out tablespaces and extents. I've checked out the extents in a database we use and came across a single table that I need to alter, here is its definition (Oracle 8i, BTW):

CREATE TABLE "CustomerTracking" (
  ProjectID               NUMBER        NOT NULL,
  BugID                   NUMBER        NOT NULL,
  SequenceNo              NUMBER        NOT NULL,
[...Bunch of fields here...],
  PRIMARY KEY ( ProjectID, BugID, SequenceNo )
    USING INDEX  PCTFREE 10
      STORAGE(INITIAL 73728 NEXT 98304 PCTINCREASE 50 )
      TABLESPACE PTADMIN)
 TABLESPACE PTADMIN PCTUSED 40 PCTFREE 10
 STORAGE(INITIAL 1040384 NEXT 8192 PCTINCREASE 0 )
 PARALLEL (DEGREE 1 INSTANCES 1) NOCACHE;

The problem I have is that now this table is 1.5 Megs large, and it used up 54 of its 101 extents allowed. It's obvious to me that NEXT 8192 PCTINCREASE 0 is culprit: The table grew over time and filled up a bunch of miniature extents.

An important consideration is that this database is 'in production', so taking the database offline is very hard, and locking the table is troublesome.

I'm sorry if this question is multi-part, it's all in the same theme. I need to know the following:
1- Can I redefine the first extent, and hopefully put all the table data into one big 1.5 meg extent?  (Requires taking the DB offline?  Locking the table?  Can it be done online?)
2- Can I redefine the NEXT extents and Pct Increase? How? (Requires taking the DB offline?  Locking the table?  Can it be done online?)
3- Any random advice for this newbie?  :)

Any example scripts would be -deeply- appreciated, I've only begun to learn this stuff.  ^n.n^