//example of how to move opportunities from one account to another
string accountId = '1MPt0000000CaRgGAK';
list<SObject> updateList = new list<Opportunity>();
for (Opportunity o : [select Id from Opportunity where AccountId =:accountId]){

    o.AccountId = '1MPt0000000CaRgGAK';
    updateList.add(o);
}
update updateList;

//example of how to delete all opportunities on certain accounts and then delete the accounts
//(can't delete the Accounts without deleting the Opptys first)
//specifically this was used to find and delete certain accounts with open or won opportunities
//if using in execute anonymous, the code to delete may have to be run multiple times if there is too much data
//if refactored into a button, bulkification is suggested
set<Id> targetAcctIds = new set<Id>();
for(Account ogAcct : [select Id, from Account where Name like '%Canad%' or Name like '%canad%']);{
targetAcctIds.add(ogAcct.Id);
}
list<Opportunity> targetOpptys = [select Id,StageName from Opportunity where AccountId in: targetAcctIds];
system.debug('$$Opportunities size: '+targetOpptys.size());
for (Opportunity o : [select Id,StageName from Opportunity where AccountId in: targetAcctIds]){
    o.StageName = 'Lost';
    targetOpptys.add(o);
}
delete targetOpptys;
list<Account> targetAccounts = [select Id from Account where Id in:targetAcctIds];
system.debug('$$targetAccounts size: '+ targetAccounts.size());
delete targetAccounts;

//example of how to delete all work orders on certain maintenance plans and then delete the maintenance plans (can't delete the MPs without deleting the WOs first)
//specifically this was used to find and delete certain renewed maintenance plans
//if using in execute anonymous, the code to delete the work orders will have to be run multiple times if there is too much data
//if refactored into a button, bulkification is suggested.
set<Id> targetMPIds = new set<Id>();
for(MaintenancePlan ogMP : [select Id,MaintenancePlanNumber, Renewed_Maintenance_Plan__c from MaintenancePlan where MaintenancePlanNumber like '%0002' or MaintenancePlanNumber like '%0003' or MaintenancePlanNumber like '%0004'  or MaintenancePlanNumber like '%0005' or MaintenancePlanNumber like '%0006' or MaintenancePlanNumber like '%0007' or MaintenancePlanNumber like '%0008' or MaintenancePlanNumber like '%0009' or MaintenancePlanNumber like '%0010' or MaintenancePlanNumber like '%0011' or MaintenancePlanNumber like '%0012'  or MaintenancePlanNumber like '%0013' or MaintenancePlanNumber like '%0014' or MaintenancePlanNumber like '%0015' or MaintenancePlanNumber like '%0016' or MaintenancePlanNumber like '%0017' or MaintenancePlanNumber like '%0018']){
 targetMPIds.add(ogMP.Renewed_Maintenance_Plan__c);
}
list<WorkOrder> targetWorkOrders = [select Id,MaintenancePlanId from WorkOrder where MaintenancePlanId in: targetMPIds limit 1000];
system.debug('$$target work orders size: '+targetWorkOrders.size());
delete targetWorkOrders;
list<MaintenancePlan> targetMaintenancePlans = [select Id from MaintenancePlan where Id in:targetMPIds];
system.debug('$$targetMaintenancePlans size: '+targetMaintenancePlans.size());
delete targetMaintenancePlans;